Long term effects of nisoldipine on the progression of coronary atherosclerosis and the occurrence of clinical events: the NICOLE study

BACKGROUND

Earlier angiographic studies have suggested that calcium antagonists may prevent the formation of new coronary lesions and the progression of minimal lesions. Conversely, a meta-analysis suggested that these drugs may increase cardiovascular mortality and morbidity in patients with coronary heart disease.

OBJECTIVE

To investigate whether nisoldipine retards the progression of coronary atherosclerosis or reduces the occurrence of clinical events.

DESIGN AND SETTING

The NICOLE study (NIsoldipine in COronary artery disease in LEuven) is a single centre, randomised, double blind, placebo controlled trial with coronary angiography at baseline, six months, and three years of follow up.

PATIENTS

826 patients who had undergone successful coronary angioplasty were randomised to nisoldipine 40 mg once daily or placebo. The intention to treat and per protocol population consisted of 819 and 578 patients, respectively.

RESULTS

In the per protocol population, 625 of the nisoldipine treated and 655 of the placebo treated patients (NS) showed angiographic progression in at least one coronary arterial segment, defined as an increase in diameter stenosis of > or = 13%. The average minimum luminal diameter of the non-dilated lesions decreased by 0.163 mm and 0.167 mm in the nisoldipine and placebo groups, respectively (NS). The respective numbers of new lesions detected were 7 and 13 (NS). In the intention to treat population, the rates of death, stroke, and acute myocardial infarction were similar in both treatment groups. However, nisoldipine use was associated with fewer revascularisation procedures and thus the percentage of patients with any clinical event was lower (44.6% v 52.6%, p = 0.02).

CONCLUSIONS

Nisoldipine has no demonstrable effect on the angiographic progression of coronary atherosclerosis or the risk of major cardiovascular events but its use is associated with fewer revascularisation procedures.

Usefulness of Nisoldipine for prevention of restenosis after percutaneous transluminal coronary angioplasty (results of the NICOLE study). NIsoldipine in COronary artery disease in LEuven

The NIsoldipine in COronary artery disease in LEuven (NICOLE) study investigates (1) whether nisoldipine, a dihydropyridine calcium antagonist, reduces the progression of minor coronary arterial lesions in the long term, and (2) whether it reduces the restenosis rate after successful percutaneous transluminal coronary angioplasty (PTCA). The NICOLE study is a single-center, randomized, double-blind trial in 826 patients, who underwent a successful PTCA. Nisoldipine 40 mg coat-core or placebo was started the morning after the procedure and continued for 3 years. All coronary arterial segments were measured on preprocedural angiogram and on the second follow-up angiogram at 3 years. On the first follow-up angiogram at 6 months only the dilated segments were measured. Although the study is still ongoing until the primary end point is reached, we report in this study the angiographic restenosis data as well as the clinical events observed at 6-month follow-up. The per-protocol population consisted of 646 patients. Restenosis, defined as a > or =50% loss of the initial gain (National Heart, Lung, and Blood Institute criterion IV) occurred in 49% and 55% of the 308 nisoldipine-treated and the 338 placebo-treated patients, respectively (p = NS). At follow-up, the rates of death and myocardial infarction were low and similar in both groups, but in the nisoldipine group, less patients required early coronary angiography (18% vs 26%, p = 0.006) and subsequent revascularization procedures (32% vs 41%, p = 0.057). Thus, nisoldipine did not significantly reduce the angiographic restenosis rate after PTCA, but reduced the number of repeat revascularization procedures, which may be due to its antianginal action.

Treatment of long dissections by use of a single long or multiple short stents: clinical and angiographic follow-up

BACKGROUND

Recently, long (> or =20 mm) coronary stents were introduced for clinical use. They are intended as an alternative to multiple conventional stents to treat extensive dissections or suboptimal results of long lesions after balloon angioplasty.

METHODS

In a total of 113 such consecutive vessels in 107 patients, the flexible Freedom stent was implanted. In 60 of these vessels, because of anatomic constraints, multiple overlapping short (16 mm) stents were implanted. The other 53 vessels were treated with a single long (> or =20 mm) stent.

RESULTS

In the single stent group there were four implantation failures (8%) successfully managed by crossover to multiple overlapping short stents. During early follow-up, in-stent thrombosis was not observed, but three patients with a single long stent and two patients with multiple overlapping stents suffered myocardial infarction as a result of long lasting myocardial ischemia during a difficult angioplasty procedure. At 6-month follow-up, > or =50% restenosis was measured in 29% and 35% of the patients with a single long stent and in those with multiple overlapping stents, respectively (not significant).

CONCLUSIONS

Compared with the alternative treatment modality (i.e., implantation of multiple short stents), no difference between in-hospital and 6-month outcome was observed. However, implantation of a single long stent, when technically feasible, reduces catheterization time, dye volume for the patient, and radiation exposure for both patient and operator during these embarrassing angioplasty procedures.

Clinical and angiographic outcome after implantation of a home-made stent for complicated coronary angioplasty

To defray the escalating costs of coronary stenting, we handmade a balloon-expandable, stainless steel stent, which after experimental evaluation, was implanted in 156 patients undergoing PTCA complicated by a major dissection. The procedural success rate was 98%. The in-hospital course was characterized by a 1.3% cardiopulmonary mortality and a 4.5% nonfatal myocardial infarction rate, while emergency bypass surgery and early repeat PTCA were necessary in only one patient each (0.6%). Clinical 6-mo follow-up in 150 patients revealed no deaths and no myocardial infarctions, and the event-free survival rate was 82%. Six-month control angiography was performed in 93.3% of eligible patients and revealed a restenosis rate of 20%.

Comparison of clinical complications, angiographic results, and device usage of coronary angioplasty using low- and high-compliance balloons

We randomized 800 patients in a prospective study comparing the angiographic results, device usage and in-hospital outcome of balloon angioplasty of primary stenoses of native coronary vessels with low-compliant and highly compliant balloons. The cumulative incidence of prespecified clinical endpoints was 8.0% in both treatment groups. The primary angiographic success rates were 83.9% and 78.9% in the high- and low-compliance group, respectively (P = 0.05). For the lesions dilated with one study balloon only, the quantitative angiographic findings were virtually identical in the two treatment groups. The total number of dissections was slightly but not significantly higher in the lesions treated with a highly compliant balloon. The global usage of angioplasty balloons was similar in both treatment groups. We conclude that, in general, there is no objective reason to prefer one balloon material to another on the basis of its compliance characteristics.

Concept of the homemade coronary stent: experimental results and initial clinical experience

To defray the escalating cost of coronary stenting, we handmade a balloon expandable coil stent with stainless steel wire. Preliminary comparison with the Palmaz-Schatz stent showed that, when implanted in porcine iliac arteries, there was no difference in immediate angiographic results or in the degree of foreign body reaction at 6 wk. Subsequently, a total of 73 stents were implanted in 52 patients, either as a bailout device (54%) or for suboptimal angiographic results (46%). All but two implantations were successful. The postprocedural regimen consisted of heparin 1,000 IU/hr, aspirin 250 mg daily, and ticlopidine 500 mg daily. In-hospital complications were limited to two groin hematomas, one necessitating blood transfusion. Importantly, stent thrombosis was not observed. While 6-mo follow-up is pending, we already conclude that a balloon expandable coil stent can be handmade easily at low cost and implanted safely in patients.

The impact of balloon material and lesion characteristics on the incidence of angiographic and clinical complications of coronary angioplasty

To assess the importance of balloon material used for percutaneous transluminal coronary angioplasty (PTCA), we compared the complication rates observed with low complaint plastomer (PM 300), intermediately compliant polyethylene (PE 600), and highly compliant polyolefin copolymer (POC) balloons. In a total of 1,650 procedures, one of these balloon materials was used to dilate 2,040 lesions. The dissection rate tended to be slightly lower with the use of more compliant balloon material. The total clinical complication rate (death, emergency coronary surgery, myocardial infarction, need for bail-out stenting or for prolonged heparin treatment, abrupt out-of-laboratory vessel closure) was 8.1%, 7.4%, and 4.2% in the procedures exclusively performed with PM 300 (N = 653), PE 600 (N = 543) and POC (N = 454) balloons, respectively (P = 0.03). In multivariate analysis, the use of less compliant balloon material emerged as an independent correlate of clinical complications (P = 0.007). However, the predictive power of the lesion complexity (B2, C versus A, B1) was four times stronger. In contrast to current concerns, the use of compliant balloon material seems at least as safe as the use of less compliant material.

Immediate and 6-month follow-up results of coronary angioplasty for restenosis: analysis of factors predicting recurrent clinical restenosis

To determine the results of coronary angioplasty for a first restenosis, the clinical, anatomic, and procedural data of 400 consecutive patients were compared with the data of 507 consecutive patients undergoing a first angioplasty. After angioplasty for restenosis, emergency redilatation had to be performed in only 0.7% of the patients versus 3.1% of the control group (p = 0.02); nevertheless, the major in-hospital event (death, myocardial infarction, emergency coronary surgery, cerebrovascular accident) rate for patients was only slightly lower (3.3% vs 4.2%, p = NS). During the 6-month follow-up period, there were no cardiac deaths and only two myocardial infarctions in the study group, but recurrent ischemia was more frequent (37% vs 31%, p = 0.05) and resulted in considerably more elective coronary surgery (16% vs 2.6%, p = 0.001). In the study group, stepwise discriminant analysis revealed four variables significantly related to the occurrence of a second restenosis: time interval between first and second angioplasty, male gender, severity of angina, and complexity of the restenotic lesions. However, their individual predictive power was low. In conclusion, compared with angioplasty for primary lesions, angioplasty for restenosis was associated with fewer periprocedural complications and, after a 6-month follow-up, serious cardiac events were almost nonexistent but recurrent ischemia was more frequent.

Effects of an ionic versus a nonionic low osmolar contrast agent on the thrombotic complications of coronary angioplasty

An increasing body of evidence suggests that the potential for thrombotic complications is greater with nonionic than with ionic contrast agents. This is a particularly important consideration in the highly thrombogenic setting of percutaneous transluminal coronary angioplasty (PTCA). To explore this issue further, 500 consecutive patients undergoing PTCA were prospectively randomized to receive the low osmolality ionic ioxaglate or the nonionic agent iohexol. The number of acute thrombotic in-laboratory events was significantly less in the ioxaglate than in the iohexol group (8 versus 18; P < 0.05), but there was no significant difference between the 2 groups as regards the number of out-of-laboratory acute rethrombotic events. With multivariate analysis, use of the nonionic agent rather than the ionic agent emerged as an independent predictor of acute in-laboratory rethrombosis. These data suggest that, in the performance of PTCA, an ionic, rather than a nonionic, should be the preferred contrast agent.

Use of an autoperfusion catheter in the treatment of acute refractory vessel closure after coronary balloon angioplasty: immediate and six month follow up results

OBJECTIVE

To determine the usefulness of the Stack autopersion dilatation catheter in patients with acute recurrent vessel closure during coronary angioplasty.

DESIGN

Prospective data collection.

SETTING

University hospital.

PATIENTS

In 37 of 1003 consecutive patients undergoing angioplasty between November 1989 and December 1990 acute vessel closure developed that could not be redilated by a conventional balloon catheter. 13 (35%) of these 37 patients were sent immediately for emergency bypass surgery.

INTERVENTION

In the remaining 24 patients an attempt was made to reopen the vessel with a Stack catheter.

MAIN OUTCOME MEASURE

Successful reopening of the vessel. All successfully treated patients were followed for at least six months to detect recurrent ischaemia.

RESULTS

In 16 patients (67%) the Stack procedure was successful. Of the eight patients in whom reopening of the occluded vessel was not achieved, seven were sent for bypass surgery and one was successfully treated by emergency stent implantation. The 16 patients successfully treated with the Stack autoperfusion system were followed up for a mean (SD) of 6.7 (2.6) (range 2 to 11) months. Ten patients remained symptom free but early clinical restenosis developed in four (25%). Overall, only three (19%) of 16 patients experienced recurrence of severe (class III-IV) symptoms and required further mechanical revascularisation.

CONCLUSION

These data support the use of the Stack autoperfusion catheter system in selected patients with acute vessel closure not responsive to attempted redilatation with conventional balloon catheters. The short-term outcome seen in this series of patients who were successfully treated with this coronary autoperfusion system is encouraging.

Coronary hemodynamics and coronary flow reserve after intracoronary diltiazem in humans

To analyze the effect of the calcium antagonist diltiazem on coronary hemodynamics, epicardial coronary artery diameter, coronary blood flow and coronary blood flow velocity were assessed at baseline and after a 0.5 mg intracoronary bolus of diltiazem in nonstenotic coronary arteries of awake humans. Patients (n = 20) were first randomized to pretreatment with either placebo (n = 10) or isosorbide dinitrate (0.5 microgram/kg/min infusion; n = 10), and coronary flow reserve was measured before and after administration of diltiazem. There were significant increases in epicardial coronary artery diameter (10%; p = 0.0001) and coronary blood flow (30%; p = 0.0001) in all patients after administration of diltiazem. Whereas basal coronary blood flow velocity increased only slightly (7%; p = not significant), there was a significant decrease in coronary flow reserve (10%; p = 0.004). Increases in coronary diameter and blood flow after diltiazem were comparable in patients pretreated with placebo or nitrates. However, the decrease in coronary flow reserve was significant only in patients pretreated with placebo (19%; p = 0.0008). This reduction in coronary flow reserve could be due to "raising the floor" (increased baseline coronary blood flow) or "lowering the ceiling" (reduction of maximal coronary blood flow).

Effects of xamoterol a new beta-adrenoceptor partial agonist, in patients with angina pectoris

The effects of xamoterol on exercise capacity have been evaluated in 10 patients with angina pectoris and well-preserved left ventricular function. Compared to placebo a single 200 mg dose of xamoterol produced a slight but insignificant increase in exercise capacity. At maximum work load, ST-T segment depression was reduced (3 mm and 2.19 mm after placebo and xamoterol, respectively; p less than 0.05). The changes paralleled an insignificant reduction in maximal heart rate and pressure-rate product. At rest, xamoterol increased the heart rate from 80 to 86 beats/min. Thus, at rest, when sympathetic tone is low, xamoterol acts as a beta-receptor agonist but during exercise, when sympathetic tone is high, xamoterol acts as an antagonist and reduces myocardial ischaemia.