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J P Carrozza

Publications and source records attributed to J P Carrozza.

At least 37 records · Page 2Linked to original sources
PubMed1998

Mechanical debulking versus balloon angioplasty for the treatment of true bifurcation lesions.

OBJECTIVES: The purpose of this study was to compare the immediate angiographic and long-term results of debulking versus balloon angioplasty for treatment of true bifurcation lesions. BACKGROUND: Previous studies have shown true bifurcation lesions to be a high risk morphological subset for percutaneous transluminal coronary angioplasty (PTCA). Although atherectomy devices have been used to treat bifurcation lesions, no studies have compared the outcomes of these alternative treatment modalities. METHODS: Between January 1992 and May 1997, we treated 70 consecutive patients with true bifurcation lesions (defined as a greater than 50% stenosis in both the parent vessel and contiguous side branch) with conventional PTCA (n = 30) or debulking (with rotational or directional atherectomy) plus adjunctive PTCA (n = 40). Paired angiograms were analyzed by quantitative angiography, and clinical follow-up was obtained in all patients. RESULTS: Acute procedural success was 73% in the PTCA group and 97% in the debulking group (p = 0.01). Major in-hospital complications occurred in two patients in the PTCA group and one in the debulking group. Treatment with atherectomy plus PTCA resulted in lower postprocedure residual stenoses than PTCA alone (16+/-15% vs. 33+/-17% in the parent vessel, and 6+/-15% vs. 39+/-22% in the side branch; p < 0.001 for both comparisons). At 1 year follow-up, the incidence of target vessel revascularization (TVR) was 53% in the PTCA group as compared with 28% in the debulking group (p = 0.05). Independent predictors of the need for repeat TVR were side branch diameter >2.3 mm, longer lesion lengths, and treatment with PTCA alone. CONCLUSIONS: For the treatment of true bifurcation lesions, atherectomy with adjunctive PTCA is safe, improves acute angiographic results, and decreases target vessel revascularization compared to PTCA alone. The benefits of debulking for bifurcation lesions were especially seen in lesions involving large side branches.

Aged↗
PubMed1998

Angiogenic potential of perivascularly delivered aFGF in a porcine model of chronic myocardial ischemia.

A number of heparin-binding growth factors, including basic (bFGF) and acidic (aFGF) fibroblast growth factors have been shown to promote angiogenesis in vivo. In this study, we employed a sustained-release polymer extravascular delivery system to evaluate the angiogenic efficacy of a novel form of genetically modified aFGF in the setting of chronic myocardial ischemia. Fifteen Yorkshire pigs subjected to Ameroid occluder placement on the left circumflex (LCX) artery were treated with perivascularly administered aFGF in ethylene vinyl acetate (EVAc) polymer (10 micrograms, n = 7) or EVAc alone (controls, n = 8). Seven to nine weeks later, after coronary angiography to document Ameroid-induced coronary occlusion, all animals underwent studies of coronary flow and global and regional left ventricular function. Microsphere-determined coronary flow in the Ameroid-compromised territory was significantly increased in aFGF-treated compared with control animals, and this improvement in perfusion was maintained during ventricular pacing. Left ventricular function studies demonstrated improved global and regional function in aFGF-treated animals. We conclude that local perivascular delivery of genetically modified aFGF results in significant improvement in myocardial flow and regional and global left ventricular function.

Animals↗
PubMed1997

Influence of gender on in-hospital clinical and angiographic outcomes and on one-year follow-up in the New Approaches to Coronary Intervention (NACI) registry.

Higher complication rates and lower success rates for treatment of women compared with men have been reported in prior studies of coronary angioplasty and in most early reports of outcome with new coronary interventional devices. In multivariate analysis this has been attributed largely to older age and other unfavorable clinical characteristics. These results are reflected in the current guidelines for coronary angioplasty. Women in prior studies have also had different distributions of vessel and lesion characteristics, but the influence of these differences on the outcome of new-device interventions have not been adequately evaluated. This article evaluates the influence of gender on clinical and angiographic characteristics, interventional procedure and complications, angiographic success, and clinical outcomes at hospital discharge and 1-year follow-up, as observed in the New Approaches to Coronary Intervention (NACI) registry. The NACI registry methodology has been reported in detail elsewhere in this supplement. This study focuses on the 90% of patients-975 women and 1,880 men-who had planned procedures with a single new device and also had angiographic core laboratory readings. Women compared with men were older, had more recent onset of coronary ischemic pain that was more severe and unstable, and had more frequent histories of other adverse clinical conditions. The distributions of several but not all angiographic characteristics before intervention were considered more favorable to angioplasty outcome in women. Differences were observed in device use and procedure staging. Angiographically determined average gain in lumen diameter after new-device intervention, with or without balloon angioplasty, was significantly less in women (1.38 mm) than in men (1.53 mm; p < 0.001); this 0.15 mm difference is consistent with the 0.16-mm smaller reference vessel lumen diameter of women. However, final percent diameter stenoses and TIMI flow and lesion compliance characteristics were similar. Among procedural complications, only treatment for hypotension, blood transfusion, and vascular repair occurred more often in women. More women than men were clinically unstable (2.1% vs 1.1%) or went directly to emergent coronary artery bypass graft surgery (CABG; 1.2% vs 0.6%) on leaving the interventional laboratory. However, in-hospital death (1.4% vs 1.1%), Q-wave myocardial infarction (MI) (0.9% vs 1.1%), and emergent CABG (1.5% vs 1.0%, for women and men, respectively) were not significantly different. Nonemergent CABG was more frequent in women (1.8% vs 0.9%; p < 0.05) and length of hospital stay after device intervention was longer (4.4 days vs 3.8 days in men; p < 0.01). In both univariate and multivariate analyses gender did not emerge as a significant variable in relation to the combined endpoint, death, Q-wave MI, or emergent CABG at hospital discharge. At 1-year follow-up more women than men reported improvement in angina (70% vs 62%) and fewer women than men had had repeat revascularization (32% vs 36%). Similar proportions were alive and free of angina, Q-wave MI and repeat revascularization (46% of women vs 45% of men). Although several procedure-related complications were more frequent in women than men after coronary interventions with new devices, no important disadvantages were observed for women in the rates of major clinical events at hospital discharge and at 1-year clinical follow-up. Additional studies are needed to evaluate the complex interplay of clinical, vessel, and lesion characteristics on success and complications of specific interventional techniques and to determine whether gender, per se, is a risk factor and whether gender specific interventional strategies may be beneficial.

Aged↗
PubMed1997

High-speed rotational atherectomy of human coronary stenoses: acute and one-year outcomes from the New Approaches to Coronary Intervention (NACI) registry.

High-speed rotational atherectomy (RA) is a new percutaneous procedure for treatment of coronary stenoses that operates by the unique mechanism of plaque abrasion. This article reports acute (in-hospital) outcomes and 1-year follow-up in a large cohort of patients treated with this device by NACI investigators. A total of 525 patients with 670 lesions treated with RA form the substrate of this report. Patients tended to be older (mean age 64.8 years) than those in previously reported series of percutaneous transluminal coronary angioplasty (PTCA), with more extensive disease and more complex lesions. Calcification was present in 54% of lesions, and eccentricity in 41%. Balloon angioplasty postdilation was performed after RA in 88% of cases. Angiographic and procedural success (angiographic success without death, Q-wave myocardial infarction [MI] or emergency coronary artery bypass graft [CABG] surgery) rates were 89% and 88%, respectively. Acute in-hospital events included 4 deaths (1%) and 1 emergency CABG surgery (0.4%). MI occurred in 6% of patients, consisting predominantly of non-Q-wave MI (5%). After RA, angiographic complications included coronary dissection (12%), abrupt closure (5%), side branch occlusion (3%), and distal embolization (3%). Most of these were resolved after postdilation except for coronary dissection, which was present in 15% of lesions treated. Mean length of stay was 3 days. At 1-year follow-up, 27% of patients required target lesion revascularization and 30% had experienced death, Q-wave MI, or target lesion revascularization. Preprocedural characteristics that independently predicted 1-year death, Q-wave MI, or target lesion revascularization were male gender, high risk for surgery, target lesions that were proximal to or in bifurcations, eccentric, long, or highly stenosed. RA, even when applied to lesions of traditionally unfavorable morphology, appears to provide reasonable procedural and angiographic success rates. Restenosis and progression of disease contribute to subsequent clinical and procedural events.

Aged↗
PubMed1997

Acute and long-term outcome after Palmaz-Schatz stenting: analysis from the New Approaches to Coronary Intervention (NACI) registry.

The randomized Stent Restenosis Study (STRESS) and Belgium Netherlands Stent (Benestent) trials established that elective use of Palmaz-Schatz stents (PSSs) in native coronary arteries with de novo lesions is associated with increased procedural success and reduced restenosis. However there are other clinical indications for which stents are commonly used (unplanned use, vein grafts, restenosis lesions) that are not addressed in these studies. From 1990-1992, 688 lesions in 628 patients were treated with PSSs in the New Approaches to Coronary Intervention (NACI) registry. Angiographic core laboratory readings were available for 543 patients (595 lesions, of which 106 were stented for unplanned indications, 239 were in saphenous vein bypass grafts, and 296 were previously treated). The cohort of patients in whom stents were placed for unplanned indications had more women, current smokers, and had a higher incidence of recent myocardial infarction (MI). Patients who underwent stenting of saphenous vein grafts were older, had a higher incidence of diabetes mellitus, unstable angina, prior MI, and congestive heart failure. Lesion success was similar in all cohorts (98%), but procedural success was significantly higher for planned stenting (96% vs 87%; p < 0.01). Predictors of adverse events in-hospital were presence of a significant left main stenosis and stenting for unplanned indication. The incidence of target lesion revascularization by 30 days was significantly higher for patients undergoing unplanned stenting due to a higher risk for stent thrombosis. Recent MI, stenting in native lesion, and small postprocedural minimum lumen diameter independently predicted target lesion revascularization at 30 days. Independent predictors of death, Q-wave myocardial infarction, or target lesion revascularization at 1 year included severe concomitant disease, high risk for surgery, left main disease, stenting in the left main coronary artery, and low postprocedure minimum lumen diameter.

Aged↗
PubMed1997

The use of the Gianturco-Roubin intracoronary stent: the New Approaches to Coronary Intervention (NACI) registry experience.

The objective of this study is to compare the in-hospital and follow-up outcome in patients receiving the Gianturco-Roubin stent (GRS) who were enrolled in the New Approaches to Coronary Intervention (NACI) registry. The GRS was approved by the US Food and Drug Administration (FDA) in August 1992 for the treatment of acute or threatened closure after a percutaneous intervention. The application of intracoronary stenting has broadened substantially in the last few years, but less is known about the use of this device for other indications. Since the NACI registry includes patients stented for other indications, a comparison of these groups with patients being stented for acute or threatened closure was undertaken. A GRS was deployed in 497 NACI registry patients. Of these, 466 patients received a GRS in 1 of 3 of the following ways: (1) 351 unplanned stenting after conventional angioplasty of the same lesion; (2) 54 after failed/suboptimal use of a new device in the same lesion; and (3) 61 in planned stenting procedures. This analysis focuses on these 3 patient subgroups and compares their in-hospital outcome and subsequent follow-up to 1 year. There were 520 stented segments in the 466 patients. The group with stenting after failed/suboptimal new-device use had a higher incidence of myocardial infarction (MI) and cardiogenic shock than either the patients with unplanned stenting after percutaneous transluminal coronary angioplasty (PTCA) or planned stenting (MI 22.2% vs 12.0% vs 0%, respectively, and cardiogenic shock 5.6% vs 0.9% vs 0%, respectively; p < 0.05). This group also had significantly lower procedural success (58.7% vs 75.3% vs 81.5%, respectively; p < 0.05). Although not statistically significant, the requirement for transfusion was higher in the unplanned and new-device stented groups than in the planned group (10.5% vs 16.7% vs 1.6%, respectively). Likewise, the incidence of Q-wave MI was higher in the new-device group (22.2% vs 12% vs 0%, respectively; p < 0.05). Despite a higher, in-hospital complication rate in the unplanned groups, follow-up from discharge to 1 year showed similar outcome. In particular, percutaneous reintervention of the stented segment occurred in: 13.0% in the unplanned after new device; 17.4% in the unplanned after PTCA; and 26.2% in the planned group. Although not statistically significant, the higher incidence of percutaneous target lesion revascularization in the planned group probably represents the greater incidence of restenotic lesions in this cohort. In this very heterogeneous group of patients, including those with failure of another new device, the use of the GRS is associated with acceptable in-hospital and follow-up complication rates, although complications were clearly greater when unplanned use of the stent was needed, particularly after failure of another new device. Although the experience is small, patients having the GRS placed in an elective fashion, i.e., the planned group, appear to experience lower in-hospital complication rates, although they have a higher rate of subsequent target lesion revascularization, in this group of predominantly restenotic lesions.

Aged↗
PubMed1997

Effect of continuous quality improvement analysis on the delivery of primary percutaneous transluminal coronary angioplasty for acute myocardial infarction.

A successful primary percutaneous transluminal coronary angioplasty (PTCA) program requires a learning process whereby the efficiency of the cardiac catheterization laboratory to deliver prompt intervention can be refined. The purpose of this study was to (1) quantify this learning process in terms of shortening the time to reperfusion, (2) examine the changes in strategy that allowed for this, and (3) determine if expedited reperfusion by primary PTCA improved patient outcomes. A database of all primary PTCA procedures was established in February 1, 1994. Continuous quality assurance analysis was performed, and program modifications introduced as needed. Patients were separated into early (group A = February 1, 1994 through January 31, 1995) and late (group B1 = February 1, 1995 through June 31, 1995, and group B2 = July 1, 1995 through December 31, 1995) cohorts. Time intervals to certain treatment landmarks were compared among groups. In-hospital outcomes were tabulated. Fifty-two consecutive patients were included (group A = 19, group B1 = 17, group B2 = 16). Time intervals shortened significantly (group A vs group B1 vs group B2) with the time from hospital presentation to first balloon inflation decreasing progressively (from 205 to 119 to 97 minutes; p <0.001). Most of this decrease was obtained by shortening the time from hospital presentation to xylocaine administration (158 to 85 to 72 minutes; p <0.005), although the time from xylocaine to first balloon inflation also decreased (from 47 to 33 to 24 minutes; p <0.005). Parallel decreases for in-hospital mortality (26% vs 0%; p = 0.004), adverse events (47% vs 18%; p = 0.05), and length of hospital stay (13.3 +/- 13.7 vs 8.4 +/- 4.4 days; p = NS) were demonstrated for groups A versus B1 and B2. A learning effect following initiation of a primary PTCA program is demonstrated in which reperfusion was more rapidly achieved as the result of procedural changes directed by quality improvement analysis with a concurrent improvement in in-hospital outcomes.

Adrenergic beta-Antagonists↗
PubMed1997

The impact of optimal stenting techniques on cardiac catheterization laboratory resource utilization and costs.

Coronary stenting has been shown to reduce angiographic restenosis and improve clinical outcomes compared with conventional balloon angioplasty, but at greater in-lab cost. Recent studies have suggested that "optimal" stent deployment can eliminate the need for intensive oral anticoagulation after stenting, with the potential to reduce vascular complications, length of stay, and hospital cost. Between January and June 1995, we performed elective 1-vessel coronary stenting in 78 patients with a single, discrete (< 15 mm) coronary stenosis (optimal single-lesion group) and in 30 patients with either a single, long stenosis or serial discrete lesions (optimal multilesion group). Compared with stent patients from the Stent Restenosis Study (STRESS) economic substudy, optimal single-lesion stenting required more stents (1.3 +/- 0.6 vs 1.1 +/- 0.4, p <0.01) and more adjunctive angioplasty balloons per patient (2.5 +/- 1.0 vs 2.0 +/- 0.9, p <0.01). As a result, catheterization laboratory costs for single-lesion stenting increased by nearly $600 between 1993 and 1995 ($4,619 +/- $1,120 [median $4,435] to $5,209 +/- $1,697 [median $4,6731, p <0.01). Compared with the STRESS angioplasty group, optimal coronary stenting increased catheterization laboratory costs by nearly $2,200 ($3,012 +/- $1,382 [median $2,548] vs $5,209 +/- $1,697 [median $4,673], p <0.01). Optimal stenting of long lesions or multiple discrete stenoses increased catheterization laboratory costs by an additional $2,000 compared with optimal single-lesion stenting ($7,201 +/- $2,428 [median $6,887] vs $5,209 +/- $1,697 [median $4,673], p <0.01). These findings demonstrate that optimal coronary stenting increases in-lab procedural resource utilization and costs compared with historical stenting techniques. Based on the downstream cost savings seen in the STRESS trial ($1,400/patient), it is unlikely that current optimal stenting techniques will result in an overall cost savings compared with balloon angioplasty.

Aged↗
PubMed1997

Percutaneous treatment of protected and unprotected left main coronary stenoses with new devices: immediate angiographic results and intermediate-term follow-up.

OBJECTIVES: We sought to evaluate the immediate angiographic results and intermediate-term follow-up after percutaneous treatment of left main coronary stenoses in the new device era. BACKGROUND: Historically, balloon angioplasty of left main coronary stenoses has been associated with high procedural morbidity and poor long-term results. It is not clear whether new devices are more effective in this anatomic setting. METHODS: Between July 1993 and July 1995, we performed initial left main coronary interventions on 46 patients (mean age 67 +/- 12 years, 26% women). Quantitative angiography was available for 42 of 46 interventions, and clinical follow-up was obtained for all patients at 1 month, 6 months and 1 year after initial revascularization. RESULTS: Most interventions (42 of 46) were performed in patients with "protected" coronary stenoses to the left coronary system owing to the presence of one or more patent left main coronary grafts. Seventy-seven percent of screened patients were deemed unsuitable for repeat coronary artery bypass surgery. Procedures performed included stenting in 73% of patients (alone in 30% and after rotational atherectomy in 43%), rotational atherectomy in 58% (alone in 15% and before stenting in 43%), directional atherectomy in 4% and angioplasty alone in 7%. Initial procedural success was achieved in all interventions, with no deaths, myocardial infarctions (creatine kinase, MB fraction > 50 IU/liter) or emergent bypass surgery. Follow-up data to date (median duration 9 months, range 6 to 19) demonstrate a 98% overall survival rate and a 6-month event-free survival rate of 78% (six target vessel revascularizations [TVRs], four non-TVRs). CONCLUSIONS: Treatment of protected left main coronary artery stenoses can be accomplished safely and effectively with new device technology. Intermediate-term follow-up demonstrates an acceptably low rate of death, myocardial infarction or repeat revascularization at 6 months and 1 year.

Aged↗
PubMed1997

Bailout and corrective use of Gianturco-Roubin flex stents after percutaneous transluminal coronary angioplasty: operator reports and angiographic core laboratory verification from the National Heart, Lung, and Blood Institute/New Approaches to Coronary Intervention Registry.

OBJECTIVES: We sought to determine the in-hospital clinical outcome and angiographic results of patients prospectively entered into the National Heart, Lung, and Blood Institute/New Approaches to Coronary Intervention (NHLBI/NACI) Registry who received Gianturco-Roubin stents as an unplanned new device. BACKGROUND: Between August 1990 and March 1994, nine centers implanted Gianturco-Roubin flex stents as an unplanned new device in the initial treatment of 350 patients (389 lesions) who were prospectively enrolled in the NHLBI/NACI Registry. METHODS: Patients undergoing implantation of the Gianturco-Roubin flex stent were prospectively entered into the Gianturco-Roubin stent portion of the NHLBI/NACI Registry. Only subjects receiving the Gianturco-Roubin stent as a new device in an unplanned fashion are included. RESULTS: The mean age of the patient group was 61.8 years, and the majority of the patients were men. A history of percutaneous transluminal coronary angioplasty (PTCA) was present in 35.4% of the group, and 16.9% had previous coronary artery bypass graft surgery. Unstable angina was present in 67.7%. Double- or triple-vessel coronary artery disease was present in 55.4%, and the average ejection fraction was 58%. The presence of thrombus was noted in 7.3%, and 7.2% had moderate to severe tortuosity of the lesion. The angiographic success rate was 92%. Individual clinical sites reported that 66.3% of the stents were placed after suboptimal PTCA, 20.3% for abrupt closure and 13.4% for some other technical PTCA failure. Major in-hospital events occurred in 9.7% of patients, including death in 1.7%, Q wave myocardial infarction in 3.1% and emergency bypass surgery in 6%. Abrupt closure of a stented segment occurred in 3.1% of patients at a mean of 3.9 days. Cerebrovascular accident occurred in 0.3%, and transfusion was required in 10.6%. Vascular events with surgical repair occurred in 8.6% of patients. CONCLUSIONS: Despite these complications, the use of this device for the treatment of a failed or suboptimal PTCA result remains promising given the adverse outcome of abrupt closure with conventional (nonstent) treatment.

Angioplasty, Balloon, Coronary↗
PubMed1997

Multivessel Palmaz-Schatz stenting: early results and one-year outcome.

OBJECTIVES: To determine whether the benefits outlined in Background might extend to patients with multivessel disease, we examined the short- and long-term outcome of multivessel Palmaz-Schatz stenting. BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) has become the dominant treatment for most patients with single-vessel coronary artery disease and has emerged as an alternative treatment for selected patients with multivessel coronary artery disease. Although multivessel angioplasty has excellent early results and low procedural complication rates, long-term outcome is tempered by the frequent need for repeat revascularization. In patients with single-vessel coronary artery disease, Palmaz-Schatz stenting has been shown to have a higher success rate and a lower restenosis rate than conventional PTCA. METHODS: A total of 103 patients (mean age 64 +/- 11 years, 78 men and 25 women) underwent stenting of 212 vessels (saphenous vein graft [53%], left anterior descending coronary artery [20%], left circumflex artery [12%] and right coronary artery [15%]). In 88 patients (85%), multivessel stenting was performed during the same procedure, whereas the remaining 15 patients (15%) had staged multivessel stenting within 1 week of the index stent. Stenting involved only native coronary arteries in 33 patients and only vein grafts in 51 patients. RESULTS: Angiographic success was achieved in 102 patients (99%). Major complications developed in three patients: one patient died, and two patients had Q wave myocardial infarction, with no emergency coronary artery bypass graft surgery or stent thrombosis. Eleven additional patients (11%) developed non-Q wave myocardial infarction, and nine patients (9%) had local vascular complications requiring surgical repair. Clinical follow-up was available in all patients at a mean of 13 +/- 8 months. At 1 year, survival was 98%, with an event-free survival rate of 80%, reflecting predominantly repeat revascularization (17% overall, with 9% target site revascularization). Multivessel native coronary stenting resulted in a higher event-free survival rate and a lower probability of repeat revascularization than did multivessel saphenous vein graft stenting. CONCLUSIONS: In selected patients, multivessel Palmaz-Schatz stenting is technically feasible and carries both excellent early results and favorable 1-year clinical outcome.

Aged↗
PubMed1997

Acute and chronic cocaine exposure can produce myocardial ischemia and infarction in Yucatan swine.

The purpose of this study was to determine whether the acute and chronic administration of cocaine could induce myocardial infarction. Twenty-five minipigs were studied before and 4 months after balloon angioplasty of the left anterior descending artery (LAD) and balloon denudation of the left circumflex artery (LCx). Minipigs received cocaine in the initial and in the 4-month study (0.1, 0.5, and 3 mg/kg i.v.). Minipigs were randomized to group I (high-cholesterol diet + daily cocaine; 500 mg i.m.; n = 8), group II (high-cholesterol diet + no i.v. cocaine; n = 5), group III (chow diet + daily cocaine; 500 mg i.m.; n = 6), group IV (chow diet + no i.v. or i.m. cocaine; n = 6). In vivo, coronary flow significantly decreased and vascular resistance significantly increased after the administration of cocaine. Histamine significantly decreased the luminal diameters (LAD and LCx) in groups I, II and III. There were a total of five acute and 16 chronic infarctions among the three groups that received either short- or long-term cocaine; however, no infarct occurred in group IV. The combination of daily cocaine abuse with a cholesterol-rich diet enhanced coronary vasoreactivity in vivo and in vitro. We conclude that long-term or sporadic cocaine abuse can induce myocardial infarction.

Animals↗
PubMed1997

Hemodynamic effects of intracoronary VEGF delivery: evidence of tachyphylaxis and NO dependence of response.

Vascular endothelial growth factor (VEGF) has been utilized to improve blood flow in the setting of myocardial or peripheral vascular ischemia. In this investigation we studied the hemodynamic effects of intracoronary VEGF administration. Hemodynamic parameters and Doppler flow wire recordings from the left anterior descending coronary artery were measured after intracoronary infusion of VEGF (1, 10, and 100 micrograms) in 28 intubated pigs. Additional studies were performed using an in vitro isolated microvessel preparation. VEGF produced a highly significant dose-dependent increase in coronary blood flow (maximal 3.51 +/- 0.85-fold) in the absence of significant changes in epicardial artery diameter, a decline in mean arterial pressure (maximal 43%), and a decrease in left ventricular end-diastolic pressure (maximal 52%), all of which could be inhibited by pretreatment with NG-nitro-L-arginine. The increase in coronary flow seen with 10 or 100 micrograms VEGF was significantly greater than the maximal vasodilation achieved with serotonin or nitroglycerin and was equivalent to a maximal adenosine response. In summary, VEGF stimulates nitric oxide (NO)-dependent dilation of coronary microvessels, and repeat administrations of VEGF resulted in rapid development of tachyphylaxis to VEGF as well as serotonin, but not to nitroglycerin or adenosine, which appeared to be secondary to impaired NO production.

Adenosine↗
PubMed1997

Basic fibroblast growth factor in a porcine model of chronic myocardial ischemia: a comparison of angiographic, echocardiographic and coronary flow parameters.

Recently, a number of growth factors including basic fibroblast growth factor (bFGF) have been shown to promote angiogenesis in vivo. In this study, we evaluated dose-dependent effect of bFGF administration in the setting of chronic myocardial ischemia. A total of 18 Yorkshire pigs subjected to ameroid occluder placement on the left circumflex artery were randomized to treatment with 10 (n = 6) or 100 microg (n = 5) of bFGF incorporated into heparin-alginate microspheres or inactive control pellets (n = 7). Eight weeks later, all animals underwent angiographic evaluation of collateral development as well as studies of coronary flow and global and regional left ventricular function. Both bFGF groups had significantly higher angiographic collateral index, TIMI flow scores and coronary flow in the ameroid-compromised territory compared with controls. Left ventricular function studies demonstrated improved global and regional function in both fibroblast growth factor groups with significantly better preservation of regional wall motion in high dose (100 microg) bFGF animals. We conclude that local perivascular delivery of bFGF results in significant improvement in myocardial function in the setting of chronic myocardial ischemia.

Animals↗
PubMed1996

Intrinsic tone as potential vascular reserve in conductance and resistance vessels.

BACKGROUND: The purpose of this study was to define the degree of intrinsic tone in conductance and resistance vessels, to define the calcium dependency of intrinsic tone in these vascular preparations, and to investigate the efficacy of vasodilatory agents on the level of intrinsic tone in these vascular preparations. METHODS AND RESULTS: All vessels were deendothelialized. Isometric force was recorded from strips of ferret aorta, ferret pulmonary artery, and human coronary artery. Vessel diameter was recorded from the ferret epicardial coronary artery and from ferret coronary microvessel in a pressurized no-flow state. Intrinsic tone was defined as the active increase in force or decrease in diameter with warming from 6 degrees C to 37 degrees C. Changes in force or diameter with various pharmacological agents were expressed as a percentage of intrinsic tone. Our results indicate that intrinsic tone accounts for approximately 35% to 40% of total tone in all vascular preparations studied and is not dependent on extracellular calcium. Agents that increased cAMP levels (eg, forskolin, milrinone) and agents that decreased protein kinase C activity (eg, staurosporine) were partially effective in decreasing intrinsic tone. Nitroprusside, adenosine, hydralazine, and nifedipine had no significant effect. CONCLUSIONS: Our results indicate that intrinsic tone represents a significant component of vascular tone that has not been previously recognized and remains largely unexploited by current pharmacological therapies.

Animals↗
PubMed1996

Stent jail: a minimum-security prison.

Small but significant side branches (particularly those with baseline ostial narrowing) may be further compromised by stent placement within parent vessel segments. Despite the theoretical risks associated with dilating branches in stent jail, the procedure was successfully completed in 84%, with minimal complications (mostly balloon rupture and local dissection) and no cases of balloon entrapment or deterioration of the final result achieved in the parent vessel.

Angioplasty, Balloon, Coronary↗