Relation of stenosis resolution pressure to long-term clinical outcome after successful percutaneous transluminal coronary angioplasty.

Variables associated with a poor long-term prognosis after successful percutaneous transluminal coronary angioplasty (PTCA) include a short duration of symptoms before PTCA, unstable angina and the presence of thrombus at the PTCA site. These imply a component of transient or dynamic obstruction as opposed to a pure fixed obstruction. It is postulated that resolution pressure (i.e., the pressure at which complete balloon inflation occurs) may also correlate with prognosis after successful PTCA. In 173 consecutive patients undergoing successful, elective, single-lesion PTCA, 48 (28%) were found to have narrowings that resolved at less than or equal to 2 atm (group 1) and 125 (72%) were found to have narrowings resolved at greater than 2 atm (group 2). There were no significant differences in baseline, anatomic or procedural variables between the 2 groups, except that angiographic coronary dissection occurred in 17% of group 1 patients versus 40% of group 2 patients (p less than 0.007). During a mean follow-up of 12.0 +/- 6.1 months, the incidence of cardiac events (repeat PTCA, coronary artery bypass grafting or myocardial infarction) was 29% in group 1 versus 15% in group 2 (p less than 0.05). The overall incidence of angina was similar between the groups (25 vs 28%), but Canadian Cardiovascular Association class 4 angina occurred significantly more frequently in group 1 than group 2 (21 vs 8%) (p less than 0.04). These data suggest that a low resolution pressure is associated with a higher incidence of unstable angina and recurrent cardiac events during follow-up than higher resolution pressures.

Recurrent ischemia more than 1 year after successful percutaneous transluminal coronary angioplasty. An analysis of the extent and anatomic pattern of coronary disease.

Of 1,181 consecutive patients who underwent successful percutaneous transluminal coronary angioplasty (PTCA) as an initial revascularization procedure and who had at least 1 year of asymptomatic follow-up, 66 (6%) underwent repeat angiography because of recurrent symptoms or evidence of exercise-induced ischemia. Patients who had revascularization procedures within 1 year of PTCA were not included in the analysis. Mean time to recurrent ischemia was 30.8 +/- 17.4 months (range 12-89 months). At follow-up, 47 patients had angina, 13 had atypical chest pain, two had acute myocardial infarction, and four had positive exercise tests without symptoms. No patient showed spontaneous regression in the extent of coronary artery disease (CAD). As compared with the extent of CAD immediately after PTCA, the extent of CAD at follow-up did not change in 26 patients (39%); it increased by one vessel in 30 (45%), by two vessels in seven (11%), and by three vessels in three (5%). The pattern of CAD seen at follow-up compared with that seen after PTCA was as follows: 18 patients (27%), no change; seven (11%), restenosis only; 30 (45%), progression of CAD at other sites only; and 11 (17%), a combination of restenosis and progression of CAD at other sites. The time to recurrence of ischemia was significantly different between those with restenosis only versus those with progression only (20.1 +/- 9.2 vs. 38.3 +/- 18.5 months) (p less than 0.009). Progression of CAD was equally distributed between dilated and nondilated vessels; however, when progression occurred in the PTCA vessel, it was significantly more likely to be distal to the PTCA site (p less than 0.008).

Coronary dissection: a predictor of restenosis?

To determine if arterial dissection resulting from transluminal coronary angioplasty (TCA) leads to a greater incidence of restenosis, 273 consecutive patients who had undergone TCA with at least 1 year of follow-up were examined. Success was graded as a greater than or equal to 20% increase in intraluminal diameter. Dissection was defined as a prominent intimal defect at the site of angioplasty. Restenosis was defined as a 50% loss of the initial angiographic gain. Of 216 patients in whom TCA was successful, 64 (30%) had dissections at the site of angioplasty and 152 (70%) had no dissection. During follow-up, 135 patients were asymptomatic with normal results of exercise tolerance tests, recurrent symptoms developed in 81 patients, and 64 patients underwent repeat angiography. The overall restenosis rate was 21%. In the dissection group, 11 (18%) had documented restenosis and 49 (82%) did not develop restenosis. In the nondissection group, 35 (24%) had documented restenosis and 113 (76%) did not develop restenosis. These data show that patients who develop dissections at the time of TCA are no more likely to develop restenosis during follow-up.

Noninvasive assessment of patients following coronary artery angioplasty.

PTCA alters the natural history of coronary artery disease and thus presents a challenge for the cardiologist to detect the variety of changes that may occur. Continuous electrocardiographic monitoring with automatic detection of ST segment changes has proved valuable during the immediate post-PTCA procedure. Radionuclide ventriculography and thallium-201 perfusion scans are most important in providing physiologic evidence of improved functional blood flow, particularly in patients with limited revascularization. Finally, the important unsolved problem with PTCA, that of restenosis, is best detected by repeat noninvasive testing in the first months after successful PTCA.

Coronary angioplasty: clinical and angiographic follow-up.

To evaluate the clinical status and restenosis rate after percutaneous transluminal coronary angiography (PTCA), 251 consecutive patients who had undergone a successful procedure from February 1979 to May 1983 were studied. Angiography was done routinely in 92 of the initial 100 consecutive patients in whom the procedure was successful (group I), 1 to 11 months (mean 6) after PTCA. Restenosis occurred in 37 of 92 patients (40%); all but 2 (who had collateral flow to the restenosed vessel) had symptoms. Conversely, 44 of 46 asymptomatic patients had no restenosis. The other 159 patients (group II) were followed up clinically, with angiography performed only if signs or symptoms of ischemia recurred. Restenosis suspected clinically and confirmed angiographically occurred in 35 of 92 patients (38%) in group I and 36 of 154 patients (23%) in group II. Of 251 patients with follow-up of at least 6 months, 109 patients (43%) became symptomatic. Of 109 symptomatic patients, 104 consented to coronary angiography; restenosis was found in 67%, progression of narrowing in other arteries occurred in 13%, and the remaining patients were presumed to have large or small vessel vasospasm. The mortality rate for the entire group was 0.8%. When repeat angioplasty was applied to patients with restenosis, over 80% of the group improved at an average follow-up time of 21 months. Symptomatic restenosis may occur less often when higher balloon inflation pressures are used during PTCA.

Exercise, electrocardiographic and functional responses after percutaneous transluminal coronary angioplasty.

Exercise testing after successful PTCA showed improved cardiac functional status on examination of electrocardiographic and symptomatic responses, myocardial perfusion and global and regional left ventricular function. Sixty-six patients were studied before and after persistently successful PTCA. Follow-up studies an average of 8 months after the successful procedure showed an incidence of abnormal testing of only 7% using both electrocardiographic and subjective symptomatic criteria during treadmill studies and no abnormal studies with thallium scintigraphy. Radionuclide cineangiography demonstrated similar left ventricular ejection fractions at rest before and after PTCA, but an improvement of 9 +/- 10% (p less than 0.001) in the exercise ejection fraction at follow-up. However, 52% of patients with paired data still had an abnormal radionuclide cineangiographic study after successful PTCA, raising the question of the presence of subclinical ischemia or a false-positive result.

Prognosis of asymptomatic or mildly symptomatic patients with coronary artery disease.

One hundred forty-seven asymptomatic or mildly symptomatic patients with coronary artery disease, who did not have significant left main coronary occlusion and had an ejection fraction greater than 20 percent, were followed up prospectively for 6 to 67 months (average 25). Significant obstruction of one coronary artery was present in 28 percent of patients, of two coronary arteries in 31 percent and of three coronary arteries in 41 percent. Ejection fraction was 55 percent or greater in 69 percent of patients. During the follow-up there were eight deaths (annual mortality rate 3 percent for the entire group, 1.5 percent for patients with single and double vessel disease but 6 percent for those with triple vessel disease). Better definition of high and low risk subgroups of patients with three vessel disease was accomplished with exercise testing. Despite a history of mild symptoms, 25 percent of the patients with triple vessel disease exhibited poor exercise capacity on exercise testing after administration of beta adrenoceptor blocking agents and nitrates was discontinued; of these, 40 percent either died (20 percent) or had progressive symptoms requiring operation (20 percent) (annual mortality rate 9 percent). Of the patients with good exercise capacity, only 22 percent either died (7 percent) or had progressive symptoms (15 percent) (annual mortality rate 4 percent). Thus, prognosis is excellent in patients with no or mild symptoms who have one or two vessel coronary disease. Patients with three vessel disease who have good exercise capacity documented by objective testing have an annual mortality rate of 4 percent. However, because patients with three vessel disease and poor exercise capacity have an extremely grave prognosis, it would appear reasonable to recommend coronary bypass surgery for this subgroup, even in the absence of supporting data derived from a definitive randomized study.

Improved myocardial function during exercise after successful percutaneous transluminal coronary angioplasty.

Fifty-nine consecutive patients with coronary-artery disease undergoing percutaneous transluminal coronary angioplasty were evaluated with radionuclide ventriculography at rest and during exercise before angioplasty (when possible) and afterward when it was successful. Thirty-eight patients (64 per cent) had an angiographically successful procedure. Three (5 per cent) had coronary occlusion as a complication. Arterial stenosis was reduced from 74 +/- 2 per cent to 31 +/- 3 per cent (mean +/- S.E.M.). The mean ejection fraction was 55 +/- 2 per cent at rest and 51 +/- 3 per cent during exercise before the procedure. After successful angioplasty, the ejection fraction was unchanged at rest but increased to 62 +/- 2 per cent (P less than 0.001) during exercise. Regional dysfunction was present during exercise in 94 per cent of the patients before the procedure and in only 8 per cent after successful angioplasty. Of the 38 patients in whom the procedure was successful, 19 had sustained improvement for over six months, and eight for three to six months. Eleven patients had recurrence of symptoms; the second angioplasty was initially successful in nine. In 24 patients remaining asymptomatic for six months (19 after the first procedure and five after the second), the left ventricular ejection fraction during exercise remained stable or improved.