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Editorial note Coronary angioplasty. How successful at improving coronary vascular reserve?
293
Internailonal Journal of Cardiology, 3 (1983) 293-294 Elsevier
Editorial
Note
Coronary angioplasty. How successful at improving coronary vascular reserve? The first successful coronary angioplasty was performed over five years ago [ 11. Analysis of the results of successful angioplasty procedures has provided new insights into the functioning of the diseased coronary circulation. In fact, coronary angioplasty provides a unique opportunity to evaluate, free of the confounding factors, the effect of abrupt changes in coronary stenoses in people with coronary artery disease.
Effects of angioplasty The study by Kanemoto et al. [2] provides good documentation that, in certain patients, successful coronary angioplasty improves the coronary circulation’s ability to increase blood flow to the affected area of myocardium. It also shows that. in some patients, the changes in myocardial function caused by inadequate myocardial perfusion at rest and during exercise may be reversible. The study also provides insight into the question of the existence of reversible asynergy. Finally, the data from the study point out that angiographic improvement in the degree of coronary obstruction does not perfectly correlate with other laboratory evidence of functional results. Clinical improvement as assessed by relief of exercise induced angina is frequently observed after successful coronary angioplasty in properly selected patients [ 11. Similar clinical improvement was observed in Kanemoto’s series in those patients in whom a successful coronary angioplasty was accomplished. In this study, exercise thallium scans performed before and after coronary angioplasty are available in 19 of 36 patients with successful angioplasties as judged by angiographic results. Overall the pooled data demonstrate that there is an improvement in the perfusion of the affected myocardial segments during exercise.
Heterogeneous
improvement
Such an improvement has previously been reported by Hirzel [3]. However, in contrast to Hirzel’s report the degree of improvement reported by Kanemoto et al. is heterogeneous.’ Many myocardial segments improved; however, other segments improved only partially and some not at all. Such an observation is not at all ’ From the Cardiac Catheterization Laboratory, Hosp. of the Univ. of Pennsylvania and the Cardiovascular Section, Dept. of Medicine, Univ. of Pennsylvania School of Medicine, Philadelphia, PA. 0167-5273/83/$03.00
0 1983 Elsevier Science Publishers B.V.
294
surprising since many of these patients were left with residual stenoses and some certainly had associated areas of infarction. The study does not analyze the relationship of the perfusion defects in the exercise scans to the redistribution scans and also does not relate the degree of exercise induced defects to the degree of residual stenosis after the angioplasty. Blood pool equilibrium gated scintigraphy again demonstrated heterogeneous results. Many patients with successful coronary angioplasty demonstrated improved ejection fractions during exercise compared to preangioplasty exercise ejection fractions. Similar results have been reported by Kent et al. [4]. Again the response of the entire group was heterogeneous, presumably for reasons similar to those of the heterogeneity of the results of the exercise thallium scanning. Interestingly, 9 of the 18 patients who had abnormal resting ejection fractions prior to angioplasty demonstrated a return of resting ejection fractions to the normal range following angioplasty. Such an observation is of interest in that it supports the concept of reversible asynergy [5] and suggests that resting left ventricular wall motion abnormalities may be in fact reversible if normal coronary artery perfusion is restored. The observation that exercise ejection fraction improves after successful coronary angioplasty is congruent with the findings of other observers [4] and again not at all surprising in view of the physiology of the situation. The data in the Kanemoto study are an elegant demonstration of the physiologic efficacy of a successful coronary artery angioplasty in the properly selected patient. The heterogeneity of the individual patient’s response to coronary angioplasty and the relation between angiographic appearance and both clinical and physiologic response have not been addressed by this study. Such questions are fertile areas for future investigation. Cardiac Catheterization Laboratory Hospital of the University of Pennsylvania 3400 Spruce Street Philadelphia, PA 19104, U.S.A.
*John
W. Hirshfeld,
Jr.
References 1 Gruentzig A, Senning A, Siegenthaler W. Nonoperative dilatation of coronary artery stenoses: percutaneous transluminal angioplasty. New Engl J Med 1979;301:61-68. 2 Kanemoto N, Her G. Kober G. Maul F-D, Klepzig H Jr, Standke R, Kaltenbach M. Noninvasive assessment of left ventricular performance following transluminal coronary angioplasty. Int J Cardiol 1983;3:281-292. 3 Hirzel HO, Nuesch K. Gruentzig AR, Luetolf UM. Short- and long-term changes in myocardial perfusion after percutaneous transluminal coronary angioplasty assessed by thallium-201 exercise scintigraphy. Circulation 1981:63: lOOI- 1007. 4 Kent KM, Bonow RO, Rosing DR, Lipson LC. Bacharach SL. Green MV. Epstein SE. Improved myocardial perfusion and function following percutaneous transluminal coronary angioplasty (abstract). Am J Cardiol 1980;45:478. 5 Helfant RH, Pine R. Meister SG, Feldman MS, Trout RG, Banka VS. Nitroglycerin to unmask reversible asynergy: correlation with post coronary bypass ventriculography. Circulation 1974:50:108-113. * Member.
Editorial
Board, International Journal of Cardiology.
Internailonal Journal of Cardiology, 3 (1983) 293-294 Elsevier
Editorial
Note
Coronary angioplasty. How successful at improving coronary vascular reserve? The first successful coronary angioplasty was performed over five years ago [ 11. Analysis of the results of successful angioplasty procedures has provided new insights into the functioning of the diseased coronary circulation. In fact, coronary angioplasty provides a unique opportunity to evaluate, free of the confounding factors, the effect of abrupt changes in coronary stenoses in people with coronary artery disease.
Effects of angioplasty The study by Kanemoto et al. [2] provides good documentation that, in certain patients, successful coronary angioplasty improves the coronary circulation’s ability to increase blood flow to the affected area of myocardium. It also shows that. in some patients, the changes in myocardial function caused by inadequate myocardial perfusion at rest and during exercise may be reversible. The study also provides insight into the question of the existence of reversible asynergy. Finally, the data from the study point out that angiographic improvement in the degree of coronary obstruction does not perfectly correlate with other laboratory evidence of functional results. Clinical improvement as assessed by relief of exercise induced angina is frequently observed after successful coronary angioplasty in properly selected patients [ 11. Similar clinical improvement was observed in Kanemoto’s series in those patients in whom a successful coronary angioplasty was accomplished. In this study, exercise thallium scans performed before and after coronary angioplasty are available in 19 of 36 patients with successful angioplasties as judged by angiographic results. Overall the pooled data demonstrate that there is an improvement in the perfusion of the affected myocardial segments during exercise.
Heterogeneous
improvement
Such an improvement has previously been reported by Hirzel [3]. However, in contrast to Hirzel’s report the degree of improvement reported by Kanemoto et al. is heterogeneous.’ Many myocardial segments improved; however, other segments improved only partially and some not at all. Such an observation is not at all ’ From the Cardiac Catheterization Laboratory, Hosp. of the Univ. of Pennsylvania and the Cardiovascular Section, Dept. of Medicine, Univ. of Pennsylvania School of Medicine, Philadelphia, PA. 0167-5273/83/$03.00
0 1983 Elsevier Science Publishers B.V.
294
surprising since many of these patients were left with residual stenoses and some certainly had associated areas of infarction. The study does not analyze the relationship of the perfusion defects in the exercise scans to the redistribution scans and also does not relate the degree of exercise induced defects to the degree of residual stenosis after the angioplasty. Blood pool equilibrium gated scintigraphy again demonstrated heterogeneous results. Many patients with successful coronary angioplasty demonstrated improved ejection fractions during exercise compared to preangioplasty exercise ejection fractions. Similar results have been reported by Kent et al. [4]. Again the response of the entire group was heterogeneous, presumably for reasons similar to those of the heterogeneity of the results of the exercise thallium scanning. Interestingly, 9 of the 18 patients who had abnormal resting ejection fractions prior to angioplasty demonstrated a return of resting ejection fractions to the normal range following angioplasty. Such an observation is of interest in that it supports the concept of reversible asynergy [5] and suggests that resting left ventricular wall motion abnormalities may be in fact reversible if normal coronary artery perfusion is restored. The observation that exercise ejection fraction improves after successful coronary angioplasty is congruent with the findings of other observers [4] and again not at all surprising in view of the physiology of the situation. The data in the Kanemoto study are an elegant demonstration of the physiologic efficacy of a successful coronary artery angioplasty in the properly selected patient. The heterogeneity of the individual patient’s response to coronary angioplasty and the relation between angiographic appearance and both clinical and physiologic response have not been addressed by this study. Such questions are fertile areas for future investigation. Cardiac Catheterization Laboratory Hospital of the University of Pennsylvania 3400 Spruce Street Philadelphia, PA 19104, U.S.A.
*John
W. Hirshfeld,
Jr.
References 1 Gruentzig A, Senning A, Siegenthaler W. Nonoperative dilatation of coronary artery stenoses: percutaneous transluminal angioplasty. New Engl J Med 1979;301:61-68. 2 Kanemoto N, Her G. Kober G. Maul F-D, Klepzig H Jr, Standke R, Kaltenbach M. Noninvasive assessment of left ventricular performance following transluminal coronary angioplasty. Int J Cardiol 1983;3:281-292. 3 Hirzel HO, Nuesch K. Gruentzig AR, Luetolf UM. Short- and long-term changes in myocardial perfusion after percutaneous transluminal coronary angioplasty assessed by thallium-201 exercise scintigraphy. Circulation 1981:63: lOOI- 1007. 4 Kent KM, Bonow RO, Rosing DR, Lipson LC. Bacharach SL. Green MV. Epstein SE. Improved myocardial perfusion and function following percutaneous transluminal coronary angioplasty (abstract). Am J Cardiol 1980;45:478. 5 Helfant RH, Pine R. Meister SG, Feldman MS, Trout RG, Banka VS. Nitroglycerin to unmask reversible asynergy: correlation with post coronary bypass ventriculography. Circulation 1974:50:108-113. * Member.
Editorial
Board, International Journal of Cardiology.