Stent placement to prevent restenosis after angioplasty in small coronary arteries.

BACKGROUND: Lesions in small-diameter vessels (<3 mm) define a group with distinct clinical and morphological characteristics. There is an inverse relationship between vessel size and angiographic restenosis rate. This study assessed whether stents reduce angiographic restenosis in small coronary arteries compared with standard balloon angioplasty. METHODS AND RESULTS: We randomly assigned 351 symptomatic patients needing dilatation of 1 native coronary vessel between 2.3 and 2.9 mm in size to angioplasty alone (n=182) or stent implantation (n=169). The primary end point was angiographic restenosis at 6 months. Secondary end points included death, myocardial infarction, bypass surgery, and target vessel revascularization in hospital and at 6 months. There were no significant differences between groups in terms of major in-hospital complications. There was a trend toward fewer in-hospital events in the stent group (3% versus 7.1% in angioplasty group, P=0.076). Crossovers to stent occurred in 37 patients (20.3%). Repeat angiography at 6-month follow-up was performed in 85.3% of patients. Angiographic restenosis occurred in 28% of the stent group and 32.9% of the angioplasty group (P=0.36). Target vessel revascularization was required in 17.8% versus 20.3% of patients (P=0.54), respectively. CONCLUSIONS: Stenting and standard coronary angioplasty are associated with equal restenosis rate in small coronary arteries. With a lower in-hospital complication rate, stenting may be a superior strategy in small vessels.

Heparin-coated Wiktor stents in human coronary arteries (MENTOR trial). MENTOR Trial Investigators.

The purpose of this study was to determine the feasibility, safety, and efficacy of elective stenting with heparin-coated Wiktor stents in patients with coronary artery disease. In experimental studies, heparin coating has been shown to prevent subacute thrombosis and restenosis. Recently, a new method of heparin coating was developed, resulting in a more stable and predictable heparin layer on stent devices. This trial constitutes the first in-human use of this coating procedure, applied on the well-known Wiktor stent device. Heparin-coated Wiktor stent implantation was performed in 132 consecutive patients (132 lesions) in a multicenter international trial from September 1996 to February 1997. Forty-three percent of patients had unstable angina, 33% had previous myocardial infarction, and 10% had diabetes mellitus. Patients were followed for 12 months for occurrence of major adverse cardiovascular events, and 96% of the eligible patients underwent quantitative angiographic control at 6 months. Stent deployment was successful in 95.5% of lesions. Minimal lumen diameter increased by 1.67 +/- 0.48 mm (from 1.02 +/- 0.38 mm before to 2.69 +/- 0.37 mm after the stent implantation). Mean percent diameter stenosis decreased from 67.4 +/- 11.3% before to 18.9 +/- 7.7% after the intervention. A successful intervention (<50% diameter stenosis and no major adverse cardiac events within 30 days) occurred in 97% of the patients. The subacute thrombosis rate was 0.8%, which compares favorably with historical controls of this stent, and a low incidence of postprocedural increase in creatine kinase-MB was noted. At 6 months, event-free survival was 85% and angiographic restenosis rate was 22% with late loss of 0.78 +/- 0.69 mm and a loss index of 0.48 +/- 0.44. Heparin-coated Wiktor stents appeared to be an efficacious device to treat Benestent-like lesions, yielding angiographic and clinical results comparable to a heparin-coated Palmaz-Schatz stent. Despite its use in more complex lesions, the incidence of subacute thrombosis appeared to be lower than historical controls with a similar noncoated stent.

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.

The conservative coronary angioplasty strategy after thrombolysis for acute myocardial infarction: immediate and short-term results.

The in-hospital and short-term follow-up results of a conservative coronary angioplasty approach in 354 consecutive patients treated after thrombolysis for acute myocardial infarction were compared with results obtained in 408 control noninfarcted patients treated for the classical indication of myocardial ischemia. Only 20% of the study patients underwent angioplasty during the initial hospitalization period and the clinical success rate was 93% versus 95% in the control group (p = NS). No significant differences in the total number of in-hospital untoward events were observed (10.2% and 7.6%, respectively). During a 7.4 +/- 1.5 month follow-up period, the total number of adverse events was only 16.9% in the study patients but it was 27.8% in the control group (p < 0.001). There were no significant differences in death, myocardial infarction, or coronary surgery as individual events, but repeat angioplasty was less frequent in the study group (14.0% versus 21.5%, p < 0.01). Thus in-hospital results in patients undergoing angioplasty on a deferred basis after thrombolysis for myocardial infarction were largely comparable with those results obtained in noninfarcted patients. Moreover, short-term clinical follow-up events were reduced when compared with the control group, an observation apparently largely related to the subgroup without clinical evidence of residual ischemia.

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.

Transluminal coronary balloon angioplasty: a useful therapeutic modality in octogenarian patients with severe angina.

In this study, the immediate and short-term outcome of 9 consecutive patients aged 80 years or older undergoing percutaneous transluminal coronary angioplasty (PTCA) are reported. Of these 9 patients, 8, despite optimal medical therapy, had unstable Class IV anginal symptoms and 6 had multivessel coronary artery disease. Primary success at PTCA (successful dilation of all attempted lesions without any complications) was achieved in 8 of the 9 (89%) patients. The one patient with unsuccessful PTCA had subsequent successful elective coronary bypass graft surgery. The 8 patients with primary success at PTCA have been followed up for a mean of 27 +/- 15 (range: 6 to 45) months. During follow-up, no patient died, required a further revascularization procedure or had a myocardial infarction. Indeed, 7 of these 8 patients have, following PTCA, remained entirely asymptomatic with no decrease in their activity level. Angina has recurred in 1 patient but it is mild and does not restrict his activities. Based on our encouraging experience we suggest that PTCA should be considered favourably in the treatment of selected octogenarian patients with severe angina poorly controlled by medical therapy.

The role of percutaneous transvenous balloon mitral valvuloplasty in the treatment of patients with symptomatic mitral stenosis.

Since its introduction in 1984, percutaneous transvenous mitral balloon valvuloplasty (PTMV) has emerged as an effective technique in the treatment of selected patients with severe mitral stenosis. The most important factors determining the haemodynamic and clinical outcome after PTMV are the anatomic and pathological features of the mitral valve apparatus. In patients with pliable, non-calcified valves, immediate success rates of well over 90% are achieved. Short-term follow-up studies of such patients after PTMV demonstrate a low rate of valve restenosis, with the vast majority of patients remaining much improved clinically. Less favourable immediate and short-term results are observed in patients who have non-pliable, calcified valves. Major acute complications of PTMV include thromboembolic events and the production of severe mitral regurgitation. It appears that, as a result of increased operator experience, better patient selection and refinements in the technique of PTMV, the rates of these acute complications are now very low. Follow-up studies will be needed to assess the long-term efficacy of the procedure. The first publications on this field are 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).

Hemodynamic changes after subselective intracoronary administration of nisoldipine in humans.

Hemodynamic changes after the subselective intracoronary administration of 50 micrograms of nisoldipine were analyzed in 24 nonstenotic coronary arteries using a randomized, placebo-controlled, double-blind protocol. The following hemodynamic parameters were studied: (a) epicardial coronary artery diameter, assessed by quantitative angiography; (b) coronary blood flow velocity, measured by an intracoronary Doppler probe; (c) coronary blood flow, calculated from the above parameters; (d) coronary flow velocity reserve, assessed after intracoronary administration of 10 mg of papaverine hydrochloride; and (e) heart rate and arterial blood pressure. Since 3 patients were excluded due to unreliable Doppler signals, a total of 21 patients was eligible for complete analysis (placebo: n = 9; nisoldipine: n = 12). In placebo-treated patients, all studied parameters proved to be very stable on repeat measurement and no significant changes were found. In nisoldipine-treated patients, a significant increase in epicardial diameter (+19%; p = 0.0001) and coronary blood flow (+47%; p = 0.003) was found. The coronary blood flow velocity transiently increased after nisoldipine, with a maximum (+80%) after 2 min and returning to baseline within 10 min. Finally, nisoldipine resulted in a significant decrease in the coronary flow velocity reserve by 20% (p = 0.001). All coronary hemodynamic effects were observed in the absence of changes in heart rate and arterial blood pressure. Therefore, the present data demonstrate that nisoldipine acts as a potent dilator of epicardial as well as resistance vessels in nonstenotic human coronary arteries.

Right coronary artery originating from distal left circumflex: an unusual feature of single coronary artery.

This report describes a patient with a single coronary artery system, in whom the right coronary artery originated from the distal left circumflex. A significant stenosis was present just at the take-off of the aberrant right coronary artery. No other associated cardiac anomaly could be demonstrated; the patient was referred for elective bypass surgery.

Changes in human coronary flow reserve after administration of intracoronary diltiazem.

Epicardial coronary artery diameter (ECAD), coronary blood flow velocity (CBFV), and coronary flow velocity reserve (CFVR) were analyzed at baseline and after a 500 micrograms i.c. bolus of diltiazem in nonstenotic coronary arteries of awake humans. Furthermore, patients (n = 25) were first randomized to pretreatment either with placebo (n = 12) or isosorbide dinitrate (0.5 micrograms/kg/min infusion) (n = 13). Diltiazem resulted in a significant increase in epicardial diameter (+10%; p = 0.001) and in coronary blood flow (CBF) (+30%; p = 0.0001). Whereas basal CBFV only slightly increased (+7%; NS), there was a significant fall in CFVR (-11%; p = 0.001). The increase in coronary diameter and CBF after administration of i.c. diltiazem was comparable in placebo- and nitrate-pretreated patients. The decrease in CFVR, however, was restricted to the placebo-pretreated patients (-21%; p = 0.0004). Apparently, diltiazem attenuated the CFVR but only in the absence of nitrates. Thus, diltiazem i.c. appears to enhance myocardial oxygen supply without deleterious effects on the distal coronary perfusion pressure.

Outcome following coronary balloon angioplasty in young adults aged 35 years or less.

The natural history of symptomatic young patients with coronary artery disease is often far from benign. Follow-up studies of young patients who have undergone coronary bypass graft surgery show frequent recurrence of symptoms and need for reoperation. Prompted by these considerations, we reviewed the records of 23 consecutive patients aged less than or equal to 35 years with symptomatic coronary artery disease, who underwent coronary balloon angioplasty at our center between August, 1984 and November, 1989. Mean patient age was 32 (3) (mean [SD]) years. Acute myocardial infarction was the first symptom of coronary artery disease in 7 (30%) of the 23 patients. At the time of angioplasty, 17 (74%) patients, had functional Class 3 or 4 anginal symptoms. Eight (35%) had multivessel coronary artery disease (stenoses greater than or equal to 70% in two or more major coronary arteries). Overall, a total of 36 critical coronary lesions were identified in 32 vessels of the 23 patients (mean of 1.6 lesions and 1.4 diseased vessels per patient). At angioplasty, dilatation of 31 lesions in 27 vessels was attempted. Multilesion angioplasty was attempted in 7 (30%) patients. Successful dilatation was achieved in 29 of the 31 (94%) lesions, and 25 of the 27 (93%) vessels. Primary clinical success (successful dilatation of all attempted lesions without any complications) was achieved in 21 of 23 (91%) patients. Three of the 21 patients with successful initial angioplasty had repeat angioplasty for restenosis.(ABSTRACT TRUNCATED AT 250 WORDS)