Evaluation of the role of coronary angioplasty in patients with unstable angina pectoris

Author

Williams DO, Riley RS, Singh AK, Gewirtz H, Most AS Reference

Am Heart J 1981; 102: 1-9 Abstract

Seventeen patients presenting with unstable angina pectoris underwent percutaneous transluminal coronary angioplasty (PTCA). Despite vigorous medical therapy, all patients were disabled with 10 experiencing refractory in-hospital angina. PTCA was judged successful in 13 patients and resulted in decreased coronary diameter narrowing from 80 ± 16% to 34 ± 13% and reduced transstenotic pressure gradient from 69 ± 13 to 23 ± 12mmHg. Regional coronary blood flow (CBF) and myocardial metabolism were assessed at rest and during pacing tachycardia in six patients with left anterior descending coronary stenosis. Prior to PTCA, neither regional CBF increased nor coronary vascular resistance declined during pacing; myocardial lactate extraction fell, indicating a shift from aerobic to anaerobic metabolism. Following PTCA, however, rapid pacing resulted in increased regional CBF, decreased coronary vascular resistance, and preservation of aerobic metabolism. Following PTCA, successfully dilated patients demonstrated marked relief of angina symptoms, increase in functional capacity, and objective exercise EKG and thallium scintigraphic evidence of relief of previously ischemic myocardium. This investigation demonstrates that PTCA, when combined with medical therapy, can be performed safely and successfully in selected patients who present with otherwise refractory unstable angina, and indicates the procedure deserves further study as a therapeutic alternative in this condition.

Summary

Seventeen carefully selected patients with unstable angina were treated by angioplasty after failure of medical therapy. In 13 of the 17, a satisfactory angioplasty result was obtained which resulted in resolution of angina; 12 of 13 remained symptom free at 2 years. In six patients with proximal left anterior descending artery (LAD) stenosis, coronary sinus catheterization, and rapid atrial pacing were used to demonstrate that in this acute setting the identified stenosis results in impaired regional blood flow and altered myocardial substrate use consistent with ischaemia. All parameters normalized after successful angioplasty of these LAD lesions.

Citation Count 118

Related References

1. Meyer J, Schmitz H-J, Kiesslich T, et al. Percutaneous transluminal coronary angioplasty in patients with stable and unstable angina pectoris: analysis of early and late results. Am Heart J 1983; 106: 973-980.

2. de Feyter PJ, Serruys PW, van den Brand M, et al. Emergency coronary angioplasty in refractory unstable angina. N Engl J Med 1985; 313: 342-346.

3. Safian RD, Snyder LD, Snyder BA, et al. Usefulness of PTCA for unstable angina after non Q-wave acute myocardial infarction. Am J Cardiology 1987; 59: 263.

4. de Feyter PJ, Suryapranata H, Serruys PW, et al. Coronary angioplasty for unstable angina: immediate and late results in 200 consecutive patients with identification of risk factors for unfavorable early and late outcome. J Am Coll Cardiol 1988; 12: 324-333.

Key message

This paper is the first demonstration that angioplasty, in addition to standard medical therapy, is a safe and effective in selected patients with unstable angina. In addition, Williams proves that stenosis on angiogram correlates with alterations in myocardial metabolism, coronary haemo-dynamics, stress testing parameters, and symptoms; and that angioplasty of the culprit stenosis returns these parameters to normal in addition to relief of symptoms. The results were durable, as only one patient had recurrent symptoms at 2 years.

Why it's important

Within 2 years of the publication of Gruentzig's first case series, Williams and colleagues show that the technique of non-surgical coronary dilatation can be safely used to treat patients with medically refractory angina. This observation dramatically expands the number of patients who are candidates for angioplasty.

Strengths

This study was remarkable (at the time) because it was the first publication of the application of angioplasty to this group of patients. It also elegantly demonstrates the functional consequences of proximal coronary stenosis relative to myocardial blood flow, haemodynamics and substrate utilization which are normalized after successful angioplasty.

Weaknesses

By today's standards, 17 patients is too small a cohort from which to draw any substantial conclusions.

Relevance

This article is the first to demonstrate that coronary stenosis identified on angiography in patients with unstable angina can be safely treated by angioplasty, with excellent short- and long-term clinical outcomes. This observation is a seminal event in the field of interventional cardiology as it applies to patients with unstable angina.

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