Physical training improves myocardial perfusion but not left ventricular function response to exercise in patients with microvascular angina

Abstract

BACKGROUND: Patients with primary microvascular angina (PMA) commonly exhibit abnormal left ventricular function (LVF) during exercise, potentially owing to myocardial ischemia. Herein, we investigated in PMA patients the effect of the reduction of myocardial perfusion disorders, by using aerobic physical training, upon LVF response to exercise. METHODS: Overall, 15 patients (mean age, 53.7 +/- 8.9 years) with PMA and 15 healthy controls (mean age, 51.0 +/- 9.4 years) were studied. All subjects were subjected to baseline resting and exercise ventriculography, myocardial perfusion scintigraphy (MPS), and cardiopulmonary testing. PMA group members then participated in a 4-month physical training program and were reevaluated via the same methods applied at baseline. RESULTS: Baseline left ventricular ejection fraction (LVEF) determinations by ventriculography were similar for both groups (PMA, 67.7 +/- 10.2%; controls, 66.5 +/- 5.4%; P=0.67). However, a significant rise in LVEF seen in control subjects during exercise (75.3 +/- 6.2%; P-0.0001) did not materialize during peak exercise in patients with PMA (67.7 +/- 10.2%; P=0.47). Of the 12 patients in the PMA group who completed the training program, 10 showed a significant reduction in reversible perfusion defects during MPS. Nevertheless, LVEF at rest (63.5 +/- 8.7%) and at peak exercise (67.3 +/- 15.9%) did not differ significantly (P=0.30) in this subset. CONCLUSIONS: In patients with PMA, reduced left ventricular inotropic reserve observed during exercise did not normalize after improving myocardial perfusion through aerobic physical training.