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P Guiteras

Publications and source records attributed to P Guiteras.

At least 19 recordsLinked to original sources
PubMed2001

Coronary endothelial dysfunction as a predictor of intimal thickening in the long term after heart transplantation.

OBJECTIVES: The mechanisms of cardiac allograft vasculopathy and its predisposing factors are multifactorial and as yet not well established. To determine the influence of endothelial dysfunction on the development of intimal thickening, we prospectively analyzed the vasomotor response to acetylcholine and nitroglycerin, as well as other donor and recipient variables. Findings were correlated with the coronary intimal thickness, which was evaluated by means of intravascular ultrasonography. METHODS: Nineteen patients who had undergone heart transplantation 4.89 +/- 2.35 years previously and who had angiographically normal coronary arteries were included. Endothelial function was analyzed by quantitative coronary analysis of the vasomotor response of the left anterior descending artery to acetylcholine. An intimal thickness index, reflecting the percentage of intima obstructing the coronary lumen, was calculated. RESULTS: Nine (47%) patients showed endothelial dysfunction, and the remaining 10 (53%) patients had a normal response. Four (44%) of 9 patients with a weight gain of greater than 20% after the operation showed endothelial dysfunction compared with none of the 10 patients with normal responses (P <.04). The severity of the intimal thickness correlated with the years after transplant (r = 0.45, P <.05). Patients with endothelial dysfunction had more intimal thickening than those without (32% +/- 17% vs 17% +/- 12%, respectively; P <.05). Furthermore, the degree of intimal thickening correlated with the magnitude of the vasomotor response to acetylcholine (r = -0.60, P =.006). No relationship was found between intimal thickness and the vasodilatory response to nitroglycerin. As independent variables for intimal thickness, multivariate analysis detected the magnitude of the response to acetylcholine (P =.0005), years after transplant (P =.01), and ischemic time (P =.03). CONCLUSIONS: Cardiac allograft vasculopathy is a multifactorial disease the severity of which increases over time. Endothelial dysfunction is a predictive factor of intimal thickening severity. Predisposing factors that provoke endothelial injury, such as perioperative ischemic time and obesity, may contribute to the development of allograft vasculopathy.

Acetylcholine↗
PubMed2000

Influence of residual stenosis in determining restenosis after cutting balloon angioplasty.

The cutting balloon is a new device for coronary angioplasty, which, by the combination of incision and dilatation of the plaque, is believed to minimize arterial wall trauma, the neoproliferative response, and subsequent restenosis. In this study, we sought to determine predictors of the restenosis using this technique. Seventy-seven patients underwent successful coronary angioplasty with cutting balloon alone. In 67 of these patients (87%), we performed a control angiogram at 6-month follow-up. Pre-, post-, and late angiographic results were evaluated by quantitative coronary analysis. Clinical and angiographic variables were correlated with restenosis as a binary variable and a continuous variable (late loss and late minimum luminal diameter). Univariate analysis showed that the immediate postprocedure minimum luminal diameter (MLD) was smaller in the restenotic group (defined as MLD > 50% by quantitative coronary angiography) than in the nonrestenotic group (1.90 +/- 0.47 mm vs. 2.19 +/- 0.56 mm, P < 0.05). In addition, the immediate percentage of stenosis was higher in the restenotic group than in the nonrestenotic group (37% +/- 10% vs. 27% +/- 11%, P < 0. 003). Multivariate analysis identified the immediate postcutting balloon percentage of stenosis as an independent determinant of binary restenosis (P < 0.008). When restenosis was defined as a continuous variable, the immediate postprocedure MLD was an independent predictor of late loss (P < 0.02) and of late MLD (P < 0. 0002). No clinical, preprocedure angiographic, or technical variables tested were associated with restenosis. The degree of postprocedural residual stenosis after cutting balloon angioplasty is predictive of late restenosis.

Adult↗
PubMed2000

Combined therapeutic strategy for multiple coronary thromboemboli.

A female with mitral valvular disease presented an acute myocardial infarction. She suddenly complained of recurrent chest pain with symptoms of pulmonary edema. The angiogram evidenced multiple coronary thromboemboli. A combined strategy using intracoronary thrombolysis, a platelet glycoprotein IIb/IIIa antagonist (abciximab) and percutaneous transluminal coronary angioplasty to help disrupt the thrombus was performed. Clinical and angiographic signs of coronary reperfusion were rapidly achieved. No bleeding complications appeared.

Abciximab↗
PubMed1999

Expanding subintimal coronary dissection under a stent-covered arterial segment: serial intravascular ultrasound observations.

A patient with an angiographically unrecognized minor coronary dissection in a stent-covered coronary segment in which a type D spiral dissection extended submedially to the distal artery is described. This complication occurred 6 months after stent implantation and was ascribed to injury of the stented vessel wall during an intravascular ultrasound study.

Aortic Dissection↗
PubMed1998

Significance of angiographic coronary dissection after cutting balloon angioplasty.

We studied 2 groups of patients with (n = 14) and without (n = 42) minor coronary dissections following cutting balloon angioplasty. Patients with a minor dissection had a longer length of lesion, higher percentage of stenosis, and greater acute gain after angioplasty; at 6-month follow-up both groups had a similar net gain and restenosis rate, suggesting that minor dissection after cutting balloon angioplasty has no influence on restenosis.

Adult↗
PubMed1998

[Initial results with the Multi-Link coronary stent].

INTRODUCTION AND OBJECTIVES: The Multi-Link intracoronary stent is a balloon-expandable stainless steel stent with an interconnected ring structure designed to provide a high degree of compressive resistance while preserving longitudinal flexibility. We present the results of our initial experience with the implantation of this stent. PATIENTS AND METHODS: From May 1996 to April 1997, 124 Multi-link stents were implanted in 97 patients. Mean age 62.2 +/- 11 years. All patients included had a coronary artery diameter > 2.7 mm. Clinical presentation includes stable angina in 20, unstable angina in 72, and myocardial infarction in 5 patients. According to the ACC/AHA classification 6 lesions were type A, 72 type B and 19 type C. The implantation of the stent was for "de novo" lesions in 85 patients and for restenosis in 12. Patients were treated after the procedure with a combination of aspirin and ticlopidine, except six of them who received aspirin and acenocumarol. 16 patients were treated additionally with Abciximab. The degree of stenosis was determined by quantitative angiography. RESULTS: The delivery of the stent was successful in all patients. The degree of stenosis before the procedure was 79.6 +/- 13.1%, and after the stent deployment was 17.7 +/- 11.4%. Three patients presented a non-Q-wave myocardial infarction, two patients had a subacute stent thrombosis, one of them died due to heart failure. During a follow-up of 4.7 +/- 2.6 months five patients were readmitted with recurrent angina (4 due to restenosis and one for vessel occlusion) and one patient with heart failure after myocardial infarction died suddenly three weeks after the dilatation. CONCLUSIONS: The Multi-Link stent was implanted successfully in all patients with a low incidence of complications, showing at the follow-up a reduced rate of clinical restenosis.

Coronary Disease↗
PubMed1998

[Coronary stent placement for recurrent angina secondary to myocardial bridging].

Myocardial bridging of the epicardic coronary arteries is not an uncommon finding in angiographic or necropsic studies. Patients who have symptoms usually improve with medical treatment. However, in refractory patients a surgical myotomy of overlying myocardium and/or a coronary bypass may be needed. We report two patients with long myocardial bridges in the mid-left anterior descending coronary artery, who had recurrent angina refractory to conventional treatment. In both patients two consecutive coronary stents were successfully implanted. At five and six months follow-up they are asymptomatic and with good exercise tolerance.

Aged↗
PubMed1995

Percutaneous transluminal coronary angioplasty as alternative treatment to coronary artery bypass surgery in iatrogenic stenosis of the left main coronary artery.

The present report describes three patients with iatrogenic left main coronary artery after aortic valve replacement. All three patients were successfully treated by percutaneous transluminal coronary angioplasty. No clinical or angiographic signs of restenosis were seen during the long-term follow-up (4, 6, and 11 years). These patients show the feasibility of percutaneous transluminal coronary angioplasty in iatrogenic left main coronary artery stenosis as alternative of coronary artery bypass surgery. However, it should be only considered in patients who would otherwise be deemed inoperable, refused reoperation, and are willing to take the risk involved.

Adult↗
PubMed1993

[8 years outcome of 243 trials of coronary angiography performed in the Montreal Institute of Cardiology].

This study reports the long-term outcome of the first 243 patients who underwent coronary angioplasty at the Montreal Heart Institute between February 1980 and March 1983. The average age of the patients was 50 +/- 9 years; one quarter of cases were unstable angina; three quarters of the patients were men. Single vessel coronary disease was present in 83% of patients; the mean ejection fraction was 62%. One segment was dilated in 216 patients and 2 segments in 27 patients. The LAD was dilated in 179 patients, the right coronary in 63 and the left circumflex artery in 20 patients. The average severity of stenosis was 83 +/- 9.5%. Angioplasty was successful in 68.7% of patients. There were no fatalities: 25.5% of patients underwent coronary bypass surgery; 6.2% of patients suffered myocardial infarction. Restenosis was observed in 28% of patients. The average follow-up period was 99 +/- 10 months (average 8 years) and ranged from 7 to 10 years. The survival rate was 98.4% and 90.5% at 5 and 10 years respectively. Survival rates without infarction were 91.8% and 81.3% at 5 and 10 years, and survival without infarction or revascularisation was 73.2% and 60.3% at 5 and 10 years, respectively. During follow-up, 80% of patients were asymptomatic. Nearly a half of patients required antianginal therapy (monotherapy in 65.7% of them). Factors associated with absence of mortality infarction or revascularisation were: female sex, absence of restenosis and less severe stenosis before angioplasty. Using a multivariate analysis, only the degree of stenosis was correlated to the absence of these complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1989

Five years of angiographic and clinical follow-up after successful percutaneous transluminal coronary angioplasty.

The first 67 consecutive patients (77 lesions) who underwent successful coronary angioplasty (PTCA) at our hospital were clinically followed with serial exercise testing over a 5-year (4 to 7) observation period. Two sequential angiographic controls were performed 6.9 +/- 4.6 (64 patients) and 49.5 +/- 21.6 (42 patients) months after PTCA. The 5-year risk of cardiac death was 8%, of myocardial infarction 2%, or coronary artery bypass grafting 16% and of repeat PTCA 8%. At 5 years, 67% of the patients remain asymptomatic. Restenosis greater than or equal to 70% diameter was observed within the first year after PTCA in 30% of the patients. Progression of coronary artery disease (CAD) was observed in 13 patients (20%). In the first angiographic control, CAD progression was 4% (3/77) in dilated and 3% (3/115) in non-dilated arteries (ns). In the second angiographic control, it was 7% (3/45) and 10% (8/81), respectively (ns). Thus good clinical and angiographic results are still observed after 5 years. Restenosis is an early, self-limited, time-restricted phenomenon that occurs in 30% of patients. Angioplasty does not appear to accelerate CAD progression.

Angina Pectoris↗
PubMed1989

Prevention of aortocoronary vein-graft attrition with low-dose aspirin and triflusal, both associated with dipyridamole: a randomized, double-blind, placebo-controlled trial.

A randomized, double-blind, placebo-controlled trial was performed in 209 patients to evaluate the efficacy of a low dose of aspirin plus dipyridamole or that of a new antiplatelet agent (triflusal) plus dipyridamole in the prevention of aortocoronary vein-graft occlusion. An angiographic control performed in 161 patients 9 days after surgery showed no significant differences between groups, but a new control on 138 of those patients 6 months later did show significant linear trends towards fewer distal anastomosis occlusions (P = 0.027) from the placebo (24%, 22/91) to the aspirin (16%, 17/106) and to the trifusal groups (12%, 10/86), and towards fewer new occlusions (P = 0.056) from 12% (9/78) to 10% (10/99) and to 2.6% (2/78), respectively, in the same groups. A multivariate logistic regression model, used to determine the effect of 33 variables on distal anastomosis occlusion at 6 months control, demonstrated that diameter of distal bed (P = 0.006), moderately to severely atherosclerotic distal bed (P = 0.003) and the interactions between poor distal bed and triflusal (P = 0.005) were independent predictors of occlusion. Thus, triflusal plus dipyridamole appeared superior to low-dose aspirin plus dipyridamole in the prevention of vein-graft occlusion, independently of coronary and vein-graft determinants of occlusion.

Adult↗
PubMed1985

Count-based scintigraphic method to calculate ventricular volumes in children: in vitro and clinical validation.

A "phantom" was used to validate 1) estimates of different depths of a constant radioactivity source, and 2) the calculation of different volumes using a constant depth and different attenuation coefficients. Using data from this in vitro study, scintigraphic estimates of right ventricular volume and ejection fraction were compared with those obtained by cineangiography in 36 children with either a normal right ventricle or various right ventricular diseases. The static program accurately estimates the distance from the radiation source to the collimator surface (r = 0.99). Radionuclide count methods best predict "phantom" volumes using attenuation coefficients between 0.11(-1) and 0.13(-1) cm. A coefficient of 0.10(-1) underestimates, whereas 0.15(-1) cm grossly overestimates actual volumes. In vivo data were therefore analyzed using an attenuation coefficient of 0.11(-1) with right ventricular counts corrected using either right ventricular or left ventricular background. Closest agreement between scintigraphic and cineangiographic volumes was obtained using right ventricular background, although end-diastolic volumes larger than 100 ml were substantially underestimated. On the basis of this study, the use of two different attenuation coefficients is suggested: the smaller 0.11(-1) cm to calculate end-systolic and end-diastolic volumes and the larger 0.15(-1) cm for volumes greater than 100 ml.

Adolescent↗
PubMed1982

Diagnostic accuracy of exercise ECG lead systems in clinical subsets of women.

The diagnostic accuracy of 14-lead exercise electrocardiography was evaluated in 112 women who had no history of myocardial infarction and underwent coronary angiography. The sensitivity of ST-segment displacement of 0.1 mV or more in any of 14 ECG leads was 0.79 for coronary artery stenosis of at least 70%; the specificity was 0.66. Results were similar using bipolar ECG leads CC5 and CM5 or 11 standard ECG leads. The ST-segment shifts that occurred only during exercise were associated with a 77% false-positive rate (10 of 13). Downsloping ST-segment depression did not provide more diagnostic information than horizontal ST-segment depression in the three clinical subsets of women. In women with typical angina pectoris, ST-segment depression of at least 0.15 mV for 0.08 second after the J point or a final treadmill time less than 360 seconds was predictive of proximal left or multivessel coronary artery disease. In the women with probable angina or nonspecific chest pain, this finding was not of diagnostic value. ST-segment elevation of 0.1 mV or more in leads V1-2 or a VL predicted proximal stenosis of at lest 80% in the left anterior descending coronary artery in all six women with typical angina pectoris. Maximal exercise testing in women with typical angina provides important diagnostic information when 11 standard ECG leads are recorded. In women with probable angina or nonspecific chest pain, diagnostic exercise testing is less useful and bipolar leads CC5 and CM5 are sufficient for most clinical purposes.

Adult↗