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Biomedical subjects

A D Pichard

Publications and source records attributed to A D Pichard.

At least 163 records · Page 9Linked to original sources
PubMed1994

Morbidity and mortality rates in elderly patients undergoing percutaneous coronary transluminal angioplasty.

Although successful dilatation of a target lesion by means of percutaneous transluminal coronary angioplasty (PTCA) can be attained as frequently in elderly as in younger patients, elderly patients have a higher risk of complications. Furthermore, cohorts of patients older than 75 years and undergoing PTCA include more women and more cases of unstable angina, factors that increase the risk of complications. Included in this analysis of 3199 PTCAs performed between January 1991 and September 1992 were 474 (14.8%) patients who were > or = 75 years old. Age was an independent risk factor for death, acute myocardial infarction, need for transfusion, and need for arterial repair after PTCA. The frequency of successful dilatation of individual lesions, emergency coronary bypass surgery, or repeated PTCA of the same lesion was not related to age. In previous studies no association has been demonstrated between age and increased risk of in-hospital reclosure. The presence of more severe coronary disease and of the greater frequency of coexisting morbid conditions makes elderly patients less able to tolerate unsuccessful or complicated PTCA.

Age Factors↗
PubMed1994

Clinical significance of distal embolization after transluminal extraction atherectomy in diffusely diseased saphenous vein grafts.

Standard balloon angioplasty of degenerated saphenous vein graft lesions may be complicated by distal embolization, particularly in the presence of intragraft thrombus. Transluminal extraction atherectomy may be useful in this setting because of its ability to remove particulate debris. This study was designed to identify the incidence and prognostic significance of distal embolization after transluminal extraction atherectomy in high-risk saphenous vein graft lesions. To address these issues the clinical course of 65 consecutive patients (86 high-risk saphenous vein graft lesions) was reviewed after extraction atherectomy. Distal embolization occurred in 11 (12.8%) of 86 high-risk lesions. The majority (63.6%) of these episodes occurred after adjunct balloon dilatation following uncomplicated use of the extraction atherectomy catheter. Correlates of distal embolization included patient age and the presence of intragraft thrombus. Major in-hospital complications developed more often in patients with distal embolization (46% vs 2% in those without distal embolization, p < 0.001), resulting in a reduced procedural success rate in this group (55% vs 91%, p = 0.01). We conclude that the risk of distal embolization after saphenous vein graft angioplasty, although potentially reduced, is not eliminated with transluminal extraction atherectomy, particularly in lesions with superimposed thrombus.

Aged↗
PubMed1994

Relation of clinical presentation, stenosis morphology, and operator technique to the procedural results of rotational atherectomy and rotational atherectomy-facilitated angioplasty.

BACKGROUND: Rotational atherectomy using the Rotablator has recently become available to treat coronary stenoses. This study was performed to determine the relation of patient characteristics, stenosis morphology, and operator technique to procedural outcome to gain insight into which patients might be best treated with this device. METHODS AND RESULTS: Four hundred stenoses from 316 patients randomly selected from the initial Rotablator experience at three major referral institutions were analyzed. Angiographic data were assessed at a central angiographic laboratory using standardized morphological criteria and caliper measurement. Patients were somewhat more elderly than most percutaneous transluminal coronary angioplasty (PTCA)-treated groups (mean age, 64 +/- 11 years), 74% were men, and the lesions treated were often complex (modified American College of Cardiology/American Heart Association lesion type A, 24%; B1, 40%; B2, 30%; and C, 6%). Elective adjunctive PTCA was used for 82% of stenoses treated. Procedural success was achieved in 89.8% of stenoses (93.5% if results with creatine kinase two to three times normal are not counted as failures), and major ischemic complications (death, 0.3%; non-Q-wave myocardial infarction, 5.7%; Q-wave myocardial infarction, 2.2%; or emergency bypass surgery, 0.9%) occurred in 8.9% of patients. Complications were due to epicardial coronary obstruction in 3.8% of patients and to delayed coronary runoff ("slow reflow") in 5.1% of patients. Procedural failure was correlated independently with outflow obstruction (success rate, 64%; odds ratio for failure, 5.4; multivariate P = .002), lesion irregularity (76%; odds ratio, 3.3; P = .003), stenosis bend > or = 60 degrees (73%; odds ratio, 3.7; P = .03), and female sex (84%; odds ratio, 2.4; P = .03). Ischemic complications were correlated independently with lesion length (> or = 50% narrowing) > or = 4 mm (complication rate, 12%; odds ratio, 3.6; multivariate P = .005), right coronary artery stenosis (13%; odds ratio, 2.4; P = .02), stenosis bend > or = 60 degrees (27%; odds ratio, 6.1; P = .03), and female sex (13%; odds ratio, 3.0; P = .04). Slow reflow was correlated with total burring duration (odds ratio, 1.005/s; multivariate P = .001), right coronary artery stenosis (incidence, 17%; odds ratio, 4.5; P = .009), and to a lesser extent with recent myocardial infarction in the treated territory (44%; odds ratio, 4.3; P = .08). CONCLUSIONS: The procedural outcome of rotational atherectomy is highly correlated with stenosis morphology and location and sex of the patient. After stratification for these parameters, overall outcome with the Rotablator appears to be similar to that with balloon angioplasty and other competing techniques. Short-term outcome with specific subsets of patients may be superior with the Rotablator (calcified stenoses), but this technique might best be avoided in some patients (those with irregular or possibly thrombus-containing stenoses, highly angulated stenoses, and possible right coronary artery stenoses or those associated with impaired distal runoff caused by a recent myocardial infarction or manifest by a fixed thallium defect).

Aged↗
PubMed1993

Clinical and angiographic outcome after directional coronary atherectomy. A qualitative and quantitative analysis using coronary arteriography and intravascular ultrasound.

To assess clinical and angiographic outcome after directional coronary atherectomy, the clinical course of 306 patients undergoing this procedure was reviewed. Directional atherectomy was successful in 290 (94.8%) procedures; complications developed in 8 (2.6%) patients. After atherectomy, percent diameter stenosis was reduced from 71 +/- 14 to 14 +/- 14% (p < 0.001) and minimal lumen diameter was increased from 0.87 +/- 0.42 to 2.55 +/- 0.57 mm (p < 0.001). In 128 (42%) patients, adjunct balloon angioplasty was performed to treat either complications or a residual stenosis > 30%. Intravascular ultrasound was also performed in 57 patients after directional atherectomy and demonstrated that a significant amount of residual plaque mass remained in lesions with a calcium arc > or = 90 degrees (17 +/- 5 mm2 vs 12 +/- 5 mm2 in lesions without calcium; p = 0.007). During the 11 +/- 6 month follow-up period, 69 (28.3%) patients developed recurrent clinical events (death, 5; Q wave myocardial infarction, 8; coronary bypass surgery, 31; coronary angioplasty, 36). Using a proportional hazards model, independent predictors of late clinical events included diabetes mellitus (relative risk [RR] = 1.95; p < 0.05), unstable angina (RR = 2.78; p < 0.005) and a prior history of restenosis (RR = 2.21; p < 0.01). We conclude that directional atherectomy is associated with high procedural success rates and infrequent complications in selected lesions subsets, although the degree of plaque resection may be limited if extensive calcium is present. Late clinical events develop in some (28%) patients after directional atherectomy, related to certain preprocedural clinical risk factors.

Atherectomy, Coronary↗
PubMed1993

Rotational coronary atherectomy after unsuccessful coronary balloon angioplasty.

The clinical and angiographic outcome of patients undergoing rotational coronary atherectomy after unsuccessful balloon angioplasty was evaluated using quantitative angiographic methods to provide insight into this procedure's mechanism of benefit. During the study period, 41 patients (50 lesions) were referred for rotational atherectomy after standard balloon angioplasty was unsuccessful. After rotational atherectomy, percent diameter stenosis was reduced from 72 +/- 14% to 41 +/- 16% (p < 0.001); adjunct balloon angioplasty was performed in 44 lesions (88%), resulting in a 25 +/- 17% final diameter stenosis (p < 0.001). The acute gain in minimal lumen diameter was 1.20 +/- 0.59 mm. In lesions needing adjunct balloon dilatation, lesion stretch was 73 +/- 27%, and elastic recoil was 22 +/- 18%, with no variation by etiology of the initial balloon failure. Overall angiographic success (< 50% residual diameter stenosis) was obtained in 49 lesions (98%). Procedural success, defined as < 50% residual diameter stenosis and the absence of major in-hospital complications (death, Q-wave myocardial infarction or emergency bypass surgery), was obtained in 37 of 41 procedures (90%); complications developed in 3 patients (7%), including 2 who needed emergency bypass surgery after development of delayed abrupt closure. It is concluded that rotational coronary atherectomy may be used in selected patients when standard balloon angioplasty is unsuccessful. Its mechanism of benefit appears related, at least in part, to changes in plaque compliance resulting from partial atheroma ablation.

Angioplasty, Balloon, Coronary↗
PubMed1993

Preliminary experience with adjunct directional coronary atherectomy after high-speed rotational atherectomy in the treatment of calcific coronary artery disease.

A high-speed rotational atherectomy was performed followed by adjunct directional atherectomy in 10 patients with symptomatic coronary artery disease and calcified target lesions and the results were evaluated using quantitative coronary arteriography and intravascular ultrasound. Target lesion calcium is common in obstructive coronary artery disease. High-speed rotational coronary atherectomy preferentially abrades noncompliant atherosclerotic plaque material, especially calcium, but often requires adjunct balloon angioplasty to achieve optimal lumen dimensions. Directional coronary atherectomy has limited efficacy in heavily calcified plaque; usually, it is a definitive primary procedure in large arteries with noncalcified target lesions. Neither of these devices alone is effective in treating calcified target lesions in large coronary arteries. Before intervention, after rotational and adjunct directional atherectomy, these measurements were obtained: quantitative coronary arteriographic measurements of minimal lumen diameter and percent diameter stenosis and intravascular ultrasound measurements of external elastic membrane, lumen, and plaque+media cross-sectional areas; percent cross-sectional narrowing; minimal lumen diameter; and target-lesion arc of calcium. With use of quantitative coronary arteriography, the preintervention minimal lumen diameter measured 0.7 +/- 0.4 mm, increased to 1.5 +/- 0.5 mm after rotational atherectomy (p = 0.0013) and to 2.5 +/- 0.3 mm after adjunct directional atherectomy (p < 0.001). The preintervention percent diameter stenosis measured 78 +/- 15%, decreased to 50 +/- 17% after rotational atherectomy (p = 0.0011), and to 17 +/- 11% (p < 0.001) after adjunct directional coronary atherectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherectomy, Coronary↗
PubMed1993

Late outcome and quality of life following percutaneous transluminal coronary angioplasty in octogenarians.

Limited data are available concerning the long-term survival and quality of life of octogenarians treated with percutaneous transluminal coronary angioplasty (PTCA). We retrospectively compared the results of PTCA in 118 octogenarians to that of 500 younger subjects. Among the octogenarians, long term follow-up was obtained including survival, relief of angina, assessment of quality of life, and capacity for independent living. These results were compared between men and women. The clinical success rate was 93% for the octogenarians and 88% for the younger patients (p = NS). The lesion success rates were 89% and 88% for these groups, respectively. Results of multilesion PTCA and dilatation of coronary occlusions were similar in both age groups. Major complication rates were 5.9% for the elderly and 3.8% for the younger patients (p < .008). Hospital mortality was higher among the octogenarians (4.6% vs 0.2%, p < .05). Among long-term octogenarian survivors, > 90% indicated a high level of satisfaction with their quality of life and health status. If needed, 88% would undergo the procedure again. Independent living was possible for 66% of these patients and automobile driving for 55%. Octogenarian men and women had similar baseline clinical characteristics, procedural success, complications, relief of angina, and survival. Women indicated a slightly lower level of satisfaction and capacity for independent living. PTCA can achieve a success rate in octogenarians comparable to that of younger patients but with an increased risk of serious complications. Patient satisfaction remains high and a majority of octogenarians remain physically active and capable of independent living.

Activities of Daily Living↗
PubMed1993

Sequential intravascular ultrasound characterization of the mechanisms of rotational atherectomy and adjunct balloon angioplasty.

OBJECTIVES: The purpose of this study was to use sequential intravascular ultrasound imaging before intervention, after rotational atherectomy and after adjunct balloon angioplasty to characterize the mechanisms of lumen enlargement after each. BACKGROUND: Rotational atherectomy uses a high speed, rotating, diamond-tipped elliptic burr to abrade atherosclerotic plaque to increase lumen size. In vitro studies have shown that high speed rotational atherectomy selectively abrades hard, especially calcified, plaque elements. However, rotational atherectomy procedures usually require adjunct balloon angioplasty. METHODS: Forty-eight lesions in 46 patients were treated with rotational atherectomy followed by adjunct balloon angioplasty in 44. Quantitative coronary arteriographic and intravascular ultrasound measurements of the target lesion were made before intervention, after rotational atherectomy and after balloon angioplasty. RESULTS: Before intervention, target lesion external elastic membrane area measured 17.3 +/- 5.9 mm2, lumen area measured 1.8 +/- 0.9 mm2 and plaque plus media area measured 15.7 +/- 4.1 mm2. After rotational atherectomy, lumen area increased, plaque plus media area decreased, arc of target lesion calcium decreased and 26% of the target lesions had dissection planes. After adjunct balloon angioplasty, external elastic membrane area increased, lumen area increased, plaque plus media area did not change and 77% of the target lesions had dissection planes. Arterial expansion was seen in 80% of lesions. The pattern of dissection plane location, which was predominantly within calcified plaque after rotational atherectomy, became predominantly adjacent to calcified plaque after adjunct balloon angioplasty (p = 0.008). CONCLUSIONS: Sequential intravascular ultrasound imaging shows that high speed rotational atherectomy causes lumen enlargement by selective ablation of hard, especially calcific, atherosclerotic plaque with little tissue disruption and rare arterial expansion. Adjunct balloon angioplasty further increased lumen area by a combination of arterial dissection and arterial expansion, especially of compliant, noncalcified plaque elements.

Aged↗
PubMed1993

Treatment of refractory coronary occlusions with a new excimer laser catheter: preliminary clinical observations.

BACKGROUND: Total coronary occlusion is a frequent cause of procedural failure after coronary angioplasty, often because of the inability to recanalize the occluded segment with a conventional coronary guidewire. The novel excimer laser catheter described in this report contains a highly efficient, pulsed excimer laser guidewire designed to create a small channel within the occluded coronary segment. A preliminary report of the safety and efficacy of this excimer laser catheter is provided. METHODS: Ten patients with refractory coronary occlusions that could not be crossed by experienced operators using conventional guidewire techniques were treated using a novel laser catheter system. The laser catheter consisted of a densely packed, multiple fiber, helical guidewire measuring 0.020 inches (0.51 mm) in diameter, interfacing a 308 nm excimer laser system and delivering 70-80 mJ/mm2 of energy to the output surface. After the laser guidewire had been advanced to the occlusion site, laser energy was applied to ablate a channel as the wire was advanced through the occlusion. Once the occlusion had been recanalized, standard concentric laser or balloon angioplasty was performed. RESULTS: Complete recanalization was achieved in three total occlusions, and partial recanalization was established in a further three; thus, normal coronary perfusion was attained in six out of 10 patients after adjunct excimer laser or balloon angioplasty. The final minimum lumen diameter averaged 1.51 mm and the final residual stenosis diameter was 27%. In two patients the procedure was unsuccessful but without significant complications; two other patients developed limited coronary perforations without clinical sequelae. CONCLUSION: Refractory coronary occlusions were successfully recanalized in six out of 10 patients using a novel excimer laser catheter. Treatment failures in four patients were not associated with major complications, although limited coronary perforation occurred in two patients.

Angioplasty, Balloon, Coronary↗
PubMed1993

Vascular complications after balloon and new device angioplasty.

BACKGROUND: Despite their potential advantages, new coronary angioplasty devices may be associated with more frequent vascular complications than noted after standard balloon angioplasty, theoretically due to the larger sheaths and prolonged periods of anticoagulation required by some of these devices. This study sought to identify the incidence, predictors, and clinical outcome of vascular complications after new device angioplasty. METHODS AND RESULTS: The clinical course of 1413 patients was reviewed after balloon or new device angioplasty. Vascular complications were defined as formation of a pseudoaneurysm, arteriovenous fistula, retroperitoneal hematoma, or groin hematoma associated with a > 15-point hematocrit drop or the need for surgical repair. Stepwise logistic regression was used to identify independent predictors for vascular complications. Vascular complications developed after 84 (5.9%) procedures; they occurred more frequently after intracoronary stenting (14.0%) and extraction atherectomy (12.5%) than after balloon angioplasty (3.2%) (odds ratios, 4.86; P < .001, and 4.26, P < .05, respectively). Independent predictors of vascular complications included the use of intraprocedural thrombolytic agents (P < .01), intracoronary stenting (P < .005), or extraction atherectomy (P < .05); high maximum creatinine level (P < .005); low nadir platelet count (P < .001); longer periods of excess anticoagulation (P < .05); and the need for repeat coronary angioplasty (P < .005). Vascular complications were not related to the size of the arterial sheath used. CONCLUSIONS: Vascular complications developed more frequently after new device angioplasty than after balloon angioplasty, with the risk for vascular complications directly related to the degree of periprocedural anticoagulation.

Aneurysm, False↗
PubMed1993

Transcatheter device synergy: preliminary experience with adjunct directional coronary atherectomy following high-speed rotational atherectomy or excimer laser angioplasty in the treatment of coronary artery disease.

We performed high-speed rotational atherectomy followed by adjunct directional atherectomy in 10 patients and excimer laser angioplasty followed by directional atherectomy in 6 patients and evaluated the results using quantitative coronary arteriography and intravascular ultrasound. Quantitative coronary arteriographic measurements of minimal lumen diameter and % diameter stenosis and intravascular ultrasound measurements of external elastic membrane, lumen, and plaque + media cross-sectional areas; % cross-sectional narrowing; minimal lumen diameter; and target-lesion arc of calcium were made pre-intervention, after rotational atherectomy or excimer laser angioplasty, and after adjunct directional atherectomy. Rotational atherectomy: Using quantitative coronary arteriography, the pre-intervention minimum lumen diameter measured 0.7 +/- 0.4 mm, increased to 1.5 +/- 0.5 mm after rotational atherectomy, and to 2.5 +/- 0.3 mm after adjunct directional atherectomy. The pre-intervention % diameter stenosis measured 78 +/- 15%, decreased to 50 +/- 17% after rotational atherectomy, and to 17 +/- 11% after adjunct directional coronary atherectomy. Intravascular ultrasound showed arcs of target lesion calcification that measured 271 +/- 92 degrees pre-intervention, decreased to 210 +/- 120 degrees after rotational atherectomy, and to 163 +/- 122 degrees after adjunct directional atherectomy, with distinct directional atherectomy cuts into calcium. Pre-intervention, target lesion external elastic membrane area measured 20.4 +/- 2.3 mm2, lumen area measured 1.5 +/- 0.6 mm2, plaque + media are measured 18.9 +/- 2.3 mm2, and % cross-sectional narrowing measured 93 +/- 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Results of coronary angioplasty using the transluminal extraction catheter.

To assess the procedural results after coronary angioplasty using the transluminal extraction catheter (TEC) in patients with complex lesion anatomy, experience with 51 patients undergoing this procedure was reviewed. One or more adverse lesion morphologic features were present in 45 patients (88%) and > or = 2 adverse features were present in 38 (74%). Procedural success (< 50% final diameter stenosis and the absence of major complications) was obtained in 42 patients (82%); major complications occurred in 7 patients (death, 3; Q-wave myocardial infarction, 4; emergency bypass operation, 2). Distal embolization was noted in 5 patients with thrombus-containing saphenous vein graft stenoses. Only lesion thrombus correlated with an unsuccessful outcome. After TEC use, diameter stenosis was reduced from 76 +/- 13 to 50 +/- 22% (p < 0.001). Adjunct balloon angioplasty was used in 44 procedures (86%), further reducing the diameter stenosis to 32 +/- 22% (p < 0.001 compared with post-TEC). High-frequency intracoronary ultrasound was performed in 11 patients after TEC use. Plaque fissuring was present in all lesions and intraluminal dissection was noted in 4 (36%). Residual plaque after TEC use was found in virtually all lesions. During the 5.2 +/- 2.8-month follow-up period, 17 patients (40%) developed recurrent symptoms. Coronary bypass surgery was performed in 4 patients and repeat coronary angioplasty was required in 3. In addition, 3 patients died from cardiac causes. It is concluded that coronary angioplasty using the TEC may be a useful alternative to balloon angioplasty in patients with complex coronary anatomy, although distal embolization may still occur in thrombus-containing saphenous vein graft lesions.

Angioplasty, Balloon, Coronary↗
PubMed1992

Target lesion calcification in coronary artery disease: an intravascular ultrasound study.

OBJECTIVES: The purpose of this study was to evaluate the frequency, amount and distribution of target lesion calcification in patients undergoing transcatheter therapy for symptomatic coronary artery disease. BACKGROUND: Coronary artery target lesion calcification may be an important determinant of response to transcatheter therapy: balloon angioplasty causes dissections in calcified lesions, directional atherectomy cuts calcium poorly, rotational atherectomy causes preferential ablation of calcium and laser irradiation effect may vary. Intravascular ultrasound imaging is a highly sensitive technique for detection of plaque calcification in vivo. METHODS: We performed intravascular ultrasound imaging before or after, or both, various transcatheter therapies in 110 patients. These 84 men and 26 women had a mean age of 60 years and a duration of angina of 22 +/- 34 months. Forty-nine patients had one-vessel, 29 had two-vessel, 25 had three-vessel and 7 had left main coronary disease. Vessels treated and imaged were the left main (n = 7), left anterior descending (n = 47), left circumflex (n = 18) and right (n = 38) coronary arteries. RESULTS: Eighty-four patients (76%) had target lesion calcification; 29 patients had one-quadrant, 25 had two-quadrant, 17 had three-quadrant and 13 had four-quadrant calcification. The calcification was superficial in 42 patients, deep in 13 and both superficial and deep in 31. The axial length of calcium could be measured in 29 patients; it was < or = 5 mm in 11 and > or = 6 mm in 18. Fluoroscopy detected calcification in 50 patients (48%, p < 0.001 vs. detection by ultrasound); this proportion increased to 74% in patients with calcification of two or more quadrants and to 86% in patients with calcification > or = 6 mm in length of two or more quadrants. Calcification was more common in patients who smoked and tended to be more common in patients with multivessel disease or previous coronary artery bypass graft surgery. CONCLUSIONS: We conclude that target lesion calcification occurs in 75% of patients with symptomatic coronary artery disease requiring angioplasty. Target lesion calcification is best detected, localized and quantified by intravascular ultrasound. These observations may be important in selecting devices for transcatheter therapy.

Adult↗