Paradoxical diminution in finger blood flow with exercise predicts adverse outcomes among patients with coronary artery disease

Abstract

Background: Whereas normal subjects increase finger blood flow during exercise (EX), patients (pts) wth coronary disease (CAD) have been shown to manifest a paradoxical decrease in fmger blood flow with EX. The clinical significance of this obsewatlon is unknown. Methods: 327 CAD pts (mean age 56 * 10,64% male) underwent EX myocardial perfusion SPECT while measuring finger blood flow using peripheral arterial tonometry. Pulse wave amplitude (PWA) ratio was assessed for each EX minute and PWA slope values were determined; slope values ~0 = vasoconstriction. SPECT scans were read blindly using a conventional 20.segment, B-point scale. A follow up of 1.86 + 1 .O years was obtaine for cardiac death, non-fatal myocardlal infarction and revascularization z-60 days after EX testing. Results: There were a total of 34 events (annualized event rate of 5,7%/year). A negative (versus positwe) slope for PWA during EX was associated with a greater frequency of cardiac events (hazards ratio 3.3 (1.2 9.5), pcO.OOl)](figure). Negative PWA slope was the most potent predictor of events by multivariate analysis, and remained so even after significant clinkxl variables including EX and SPECT results, were forced first into the analysis (adjusted risk ratlo = 2.62 [1.07,6.42]). Conclusions: Paradoxical decrease in finger blood flow during EX is associated with an increased frequency of cardiac events. Moreover, this measure adds incremental value to existing clinical and exercise SPECT data for cardiac risk assessment