Jacques Crépeau

Restenosis after successful percutaneous transluminal coronary angioplasty: The montreal heart institute experience

Repeat coronary angiography was performed within 6 months after successful percutaneous transluminal coronary angioplasty (PTCA) in 178 of our first 181 patients (98%). The remaining 3 patients were symptom free, had negative treadmill exercise test results and were considered not to have had restenosis. A second follow-up angiogram was performed in 107 patients (59%), including all patients with persistent or recurrent anginal symptoms, between 7 and 18 months after PTCA. Fifty-one of the 181 patients (28%) had restenosis on 51 of 205 successfully dilated segments (25%). The stenosis was greater than or equal to 70% in 49 of these 51 segments; it was 65% and 55%, respectively, in the 2 remaining patients. Restenosis was documented angiographically at a median time of 4.7 +/- 4 months. However, 47 patients (92%) had restenosis documented within 6 months, 2 between 7 and 12 months and 2 between 13 and 18 months after PTCA. Stepwise logistic regression analysis selected the following factors as independent predictors of restenosis after PTCA: variant angina, multivessel disease, severity of residual stenosis and less reduction in the diameter of the stenosis on the angiogram immediately after PTCA. Of these 4 factors, the degree of residual stenosis immediately after PTCA was by far the most significant. It is concluded that restenosis occurs in approximately 25% of patients, almost always within the first 6 months, after successful PTCA. The degree of residual stenosis after PTCA is the most important predictor of restenosis. Increased experience and improved instrumentation may eventually lead to less residual stenosis and better late results after PTCA.

Effects of Probucol on Vascular Remodeling After Coronary Angioplasty

BACKGROUND We have shown that probucol reduces restenosis after balloon angioplasty. Whether probucol acted via prevention of neointimal formation or improvement in vascular remodeling could not be addressed by angiography and required the use of intravascular ultrasound (IVUS). METHODS AND RESULTS Beginning 30 days before angioplasty, 317 patients were randomly assigned to receive probucol, multivitamins, combined treatment, or placebo. Patients were then treated for 6 months after angioplasty. IVUS examination was performed immediately after angioplasty and at follow-up in 94 patients (111 segments). The cross section selected for serial analysis was the one at the angioplasty site with the smallest lumen area at follow-up. In the placebo group, lumen area decreased by -1. 21+/-1.88 mm2 at follow-up, and wall area and external elastic membrane (EEM) area increased by 1.50+/-2.50 and 0.29+/-2.93 mm2, respectively. Change in lumen area, however, correlated more strongly with the change in EEM area (r=0.53, P=0.002) than with the change in wall area (r=-0.13, P=0.49). Lumen loss was -1.21+/-1.88 mm2 for placebo, -0.83+/-1.22 mm2 for vitamins, -0.25+/-1.17 mm2 for combined treatment, and -0.15+/-1.70 mm2 for probucol alone (P=0.002 for probucol, P=0.84 for vitamins). Change in wall area was similar for all groups. EEM area increased by 0.29+/-2.93 mm2 for placebo, 0. 09+/-2.33 mm2 for vitamins only, 1.17+/-1.61 mm2 for combined treatment, and 1.74+/-1.80 mm2 for probucol only (P=0.005 for probucol). CONCLUSIONS Lumen loss after balloon angioplasty is due to inadequate vessel remodeling in response to neointimal formation. Probucol exerts its antirestenotic effects by improving vascular remodeling after angioplasty.

Exercise electrocardiography and myocardial scintigraphy in the serial evaluation of the results of percutaneous transluminal coronary angioplasty.

The diagnostic value of exercise electrocardiography using 14 leads and thallium‐201 scintigraphy were evaluated in 54 of 70 patients who underwent percutaneous transluminal coronary angioplasty (PTCA), both in the initial assessment and serial follow‐up of patients after PTCA. Of the 45 patients who had successful PTCA, 36 had complete noninvasive studies performed before and 1 month after PTCA. Thirty‐three of these 36 were asymptomatic 1 month after PTCA; the number of patients with an abnormal exercise ECG decreased from 20 to seven (p < 0.01) and with an abnormal thallium‐201 scintigram from 21 to six (p < 0.001); the number of patients who had at least one of the two tests positive decreased from 26 to 10. The average treadmill time increased from 448 ± 183 to 618 119 seconds (i < 0.001), and the average rate‐pressure product increased from 19.81 ± 6.4 to 31.35 4.6 units × 10 (p < 0.001). Of the 10 patients with a positive test, two had a partial restenosis ⩾ 50% but < 70% on the 6‐month control angiogram; two had a residual stenosis ⩾ 50% in a vessel that was not dilated and three had an abnormal scintigram before and 1 month after PTCA that subsequently became negative at 6 months. Six months after PTCA, a control angiogram was performed in 20 asymptomatic patients; 18 had an excellent PTCA result and two had a partial restenosis ⩾ 50% but < 70%. The stress test results were normal in patients with a successful 6‐month PTCA and abnormal in the two patients with a partial restenosis. Ten patients redeveloped angina within 3 months of PTCA; nine developed a restenosis ⩾ 60% and one had a 90% left circumflex stenosis that could not be dilated or grafted. Six of the 10 patients had a normal exercise ECG and scintigram at 1 month that became abnormal when symptoms reappeared. The ratepressure product before PTCA and when angina symptoms recurred was similar (18.00 ± 2.20 vs 23.58 ± 6.7 units × 103) (NS). In conclusion, the use of clinical symptoms in conjunction with the physiologic data, ECG and myocardial scintigram acquired during exercise provide important short‐term data on the angiographic evolution of PTCA results. The noninvasive tests may be useful in determining guidelines for repeat angiography in patients who have had PTCA.

Reduced pulmonary clearance of endothelin-1 in pulmonary hypertension

OBJECTIVE Pulmonary hypertension (PHT) is associated with increased endothelin-1 (ET-1) levels that correlate with the severity of the disease. The pulmonary circulation is an important site for ET-1 metabolism and may modulate plasma ET-1 through an increase in production, a reduction in removal, or a combination of both. We measured and compared pulmonary metabolism of circulating ET-1 in controls and in patients with PHT. METHODS AND RESULTS The indicator-dilution technique was combined with measurements of ET-1 levels to quantify pulmonary metabolism of ET-1 in controls (n = 13) and in patients with PHT (n = 17). ET-1 levels doubled in PHT (p < 0.05) and, although there was no difference between aortic and pulmonary artery levels in controls (0.68+/-0.09 and 0.61+/-0.08 pg/ml, respectively, p = 0.22), they tended to be higher in PHT (1.23+/-0.26 vs 1.07+/-0.19 pg/ml, p = 0.08). Pulmonary extraction of tracer iodine-125-ET-1 was reduced from 47%+/-2.0% in the controls to 34%+/-3.6% in PHT (p = 0.005) and inversely correlated with the severity of pulmonary hypertension (r = -0.524, p = 0.03). Consequently, circulating ET-1 clearance was reduced by PHT from 1424+/-77 ml/min to 892+/-119 ml/min (p < 0.001). Pulmonary production of circulating ET-1 (in picograms per minute) was not different but the quantity of ET-1 that survives passage through the lungs was increased by PHT (1860+/-359 pg/min vs 992+/-152 pg/min, p = 0.037). CONCLUSION PHT is associated with a reduced pulmonary clearance of ET-1 that contributes to the increase in circulating levels.

Percutaneous transluminal coronary angioplasty in patients with variant angina.

Among the first 83 patients treated with percutaneous transluminal coronary angioplasty (PTCA) at our institution, typical variant angina was recognized beforehand in five cases and was discovered within 4 months of PTCA in six others. All patients had a 65-95% proximal left anterior descending coronary artery stenosis and only one had a coronary lesion >50% in other coronary arteries. Before PTCA, all patients were premedicated with calcium-antagonist drugs. Thirteen of 15 PTCAs, including three of four repeat PTCAs, were technically successful. However, variant angina recurred after successful PTCA in three of the five patients in whom it was documented beforehand and in an additional two of two patients with variant angina before a successful repeat PTCA. Overall, among the nine patients with variant angina after successful PTCA, five had restenosis at the site of PTCA and two others developed severe lesions adjacent to the site of PTCA within 4 months of the procedure. The three patients without restenosis have been treated with calcium-antagonist drugs from soon after PTCA and have remained angina-free. These results suggest that PTCA is technically feasible in patients with variant angina who have organic lesions, but symptoms due to coronary spasm usually persist or recur, often with restenosis.

Multiple coronary angioplasty: A model to discriminate systemic and procedural factors related to restenosis

To assess the interrelation of clinical and procedural factors responsible for restenosis, 119 patients undergoing coronary arteriography were studied a mean of 5.8 +/- 3 months after successful multiple percutaneous transluminal coronary angioplasty. In all clinical, angiographic and procedural variables, the 119 patients undergoing repeat catheterization were similar to the 87 patients that did not. Overall, restenosis occurred in 74 (34%) of 215 lesions. Sixty-three patients had no restenosis, 44 had at least one restenosis and 12 had restenosis at all angioplasty sites. The statistical distribution of restenoses did not follow a binomial model, suggesting that restenosis is more than a lesion-specific phenomenon. Of all the clinical and procedural variables assessed by multivariate logistic regression analysis, only percent stenosis before angioplasty (p less than 0.01), diabetes mellitus (p less than 0.01) and percent stenosis after angioplasty (p less than 0.05) were predictive of restenosis in the entire group. Patients with no restenosis and patients with restenosis at all sites were not different with respect to procedural variables; however, patients with restenosis at all sites more often (p less than 0.05) had diabetes and recent onset angina. In contrast, patients with no restenosis differed from patients with isolated restenosis with respect to procedural variables: severity of stenosis before and after angioplasty, balloon/artery lumen ratio and maximal inflation pressure. Thus, procedural factors may be more related to isolated restenosis, but patient-related factors such as diabetes and recent onset angina may play a more important role in patients with multiple restenoses.

Left-to-right atrial shunting after percutaneous mitral valvuloplasty. Incidence and long-term hemodynamic follow-up.

To assess the incidence and long-term evolution of left-to-right atrial shunting (AS) after the performance of percutaneous mitral valvuloplasty (PMV), venovenous indicator dilution curves and right heart oximetric measurements were obtained in 68 consecutive patients before and after successful PMV. The procedure increased the mitral valve area (p less than 0.0001) and decreased the mitral gradient (p less than 0.0001). No AS was detected before PMV, but it was detected immediately after PMV. Oximetry identified AS in 17 patients (25%), and dilution curves identified AS in an additional 25 (total, 62%). The ratio of mean pulmonary to systemic blood flow (Qp/Qs) was 1.31 +/- 0.2, and in six patients (9%), the ratio was 1.5 or greater. Among nine clinical, 20 hemodynamic, and six procedural variables, stepwise logistic regression analysis selected the following as independent predictors of AS: smaller increases in valve area (p = 0.01) after PMV, absence of previous surgical commissurotomy (p = 0.02), mitral valve calcification (p = 0.02), and smaller left atria (p = 0.06). Among the 33 patients recatheterized at 6 months, oximetry had detected AS in 10, and dilution curves detected AS in an additional nine (total, 58%) immediately after PMV. At 6 months, AS had decreased or disappeared in 14 of these patients (74%), had increased in three (16%), and was unchanged in two (10%). Overall, at 6 months, oximetry identified AS in three patients, and dilution curves identified AS in an additional 13 (total, 48%). AS was detected at 6 months in only three patients but was not detected immediately after PMV. Although AS is very frequent immediately after PMV, Qp/Qs is usually less than 1.5. The appearance of shunting correlates with patient characteristics and with less improvement in valve area after PMV. Atrial shunting usually persists at 6 months, but its severity almost always decreases.

Percutaneous mitral valve annuloplasty for ischemic mitral regurgitation: First in man experience with a temporary implant

Objective: This study evaluated human feasibility and acute efficacy of a novel percutaneous transvenous mitral annuloplasty (PTMA™) device (Viacor) placed temporarily in the coronary sinus (CS): the implant allows in‐situ incremental adjustment to optimally reduce the anterior–posterior mitral annulus (MA) dimension, and improve leaflet co‐aptation and reducing mitral regurgitation (MR). Background: Surgical annuloplasty remains the standard treatment of severe ischemic MR but its application is limited by high morbidity and mortality. The effectiveness of PTMA device (Viacor) to reduce MR in the short‐term has been demonstrated in animals studies but not in humans. Methods: Symptomatic patients with ischemic MR graded 2+ to 4+ requiring surgical mitral annuloplasty were screened. Patients with any mitral leaflet or mitral apparatus abnormality were excluded. Preoperatively, under general anesthesia and transesophageal echocardiography guidance, a temporary PTMA device was placed via the right internal jugular or subclavian vein. Results: Four patients were studied. After device placement and adjustment, regurgitant volume was substantially reduced (45.5 ± 24.4 to 13.3 ± 7.3 ml) via MA anterior–posterior diameter reduction (40.75 ± 4.3 to 35.2 ± 1.6 mm) in 3 patients. In one patient, the PTMA device could not be deployed due to extreme angulated anatomy. Conclusions: PTMA in human is feasible and reduces ischemic MR (to grade 1+) by reducing MA anterior–posterior diameter. Temporary placement of the PTMA device may assist in the development of permanent implants and ensure optimal efficacy.

Long-term angiographic follow-up after angioplasty of venous coronary bypass grafts

From April 1981 to June 1987, 57 patients underwent venous coronary bypass graft percutaneous angioplasty and had a minimal follow-up of 18 months. The procedure was elective for 28 patients, urgent for 19, and was considered as an emergency for 10. A total of 64 grafts were dilated that had been bypassed 58 +/- 48 months previously (range 2 to 184 months); lesions were located on the aortic anastomosis in 12 grafts, on the body in 38, and on the coronary anastomosis in 14. Technical success was 95.3% (61 of 64) per lesion; clinical success was 84.4% (54 of 64) per lesion and 82.5% (47 of 57) per patient. Thrombotic complications with images of a lacunar defect occurred in 11 grafts (17.2%). Predictive factors for these complications were: age of grafts 38.5% for greater than 60 month grafts versus 2.6% for less than 60 month grafts (p less than 0.01); site of lesion, body lesion 28.9% versus anastomosis none (p less than 0.01); type of lesion, concentric and short 6% versus other 29% (p less than 0.05); and recent fibrinolysis in 66% versus 10.6% (p less than 0.05). Long-term follow-up is available in the 47 successful patients and the three limited non-Q wave myocardial infarction patients. Two patients died at 13 and 17 months. Long-term angiographic follow-up is available in 45 of 48 patients or 94%. At the end of the study, 35 of 57 (61.4%) venous bypass grafts in 32 patients (64%) were patent after one or more percutaneous transluminal angioplasties.(ABSTRACT TRUNCATED AT 250 WORDS)

Restenosis and progression of coronary atherosclerosis after coronary angioplasty

The relation between restenosis and progression of atherosclerosis in other coronary segments after angioplasty was studied in 98 consecutive patients with 110 coronary stenoses successfully treated with angioplasty. At early angiographic restudy (5 +/- 2 months after angioplasty) 37 patients (38%) had restenosis (defined as a stenosis greater than or equal to 50% of the luminal diameter or loss of greater than or equal to 50% of the gain achieved by angioplasty); progression of atherosclerosis was observed in 4 patients with and 7 without restenosis (13 versus 11%, p = NS). Ninety of the 98 patients underwent a late angiographic restudy a mean of 34 +/- 11 months after angioplasty. Late restenosis was found in one patient. Progression of coronary artery disease (defined as a greater than or equal to 20% decrease in the diameter of a vessel initially narrowed by greater than or equal to 50% or a greater than or equal to 30% decrease when the initial stenosis was less than 50%) was examined in relation to restenosis in 85 of the 90 patients. It occurred in 9 of 27 patients with and 22 of 58 patients without restenosis (33 versus 38%, p = NS). Restenosis developed more rapidly than did progression of disease. Diameter stenosis increased from 35 +/- 8 to 73 +/- 11% at the early restudy in lesions with restenosis; in lesions with disease progression it increased from 9 +/- 18 to 20 +/- 28% (p less than 0.001) at the early restudy to 53 +/- 21% (p less than 0.001) at the late restudy.(ABSTRACT TRUNCATED AT 250 WORDS)