Percutaneous aortic valve replacement immediately restored coronary physiological reserve, reversing the abnormal decline in diastolic suction wave during increased heart rate (P=0.014).
Observational (n=11)
Does percutaneous aortic valve replacement improve coronary physiological reserve in patients with aortic stenosis and unobstructed coronary arteries?
PAVR immediately restores normal coronary physiological reserve in response to increased heart rate, providing a mechanistic explanation for the relief of angina in patients with aortic stenosis and unobstructed coronaries.
Absolute Event Rate: 1.1% vs 1.9%
p-value: p=0.02
BACKGROUND: Aortic stenosis causes angina despite unobstructed arteries. Measurement of conventional coronary hemodynamic parameters in patients undergoing valvular surgery has failed to explain these symptoms. With the advent of percutaneous aortic valve replacement (PAVR) and developments in coronary pulse wave analysis, it is now possible to instantaneously abolish the valvular stenosis and to measure the resulting changes in waves that direct coronary flow. METHODS AND RESULTS: Intracoronary pressure and flow velocity were measured immediately before and after PAVR in 11 patients with unobstructed coronary arteries. Using coronary pulse wave analysis, we calculated the intracoronary diastolic suction wave (the principal accelerator of coronary blood flow). To test physiological reserve to increased myocardial demand, we measured at resting heart rate and during pacing at 90 and 120 bpm. Before PAVR, the basal myocardial suction wave intensity was 1.9±0.3×10(-5) W · m(-2) · s(-2), and this increased in magnitude with increasing severity of aortic stenosis (r=0.59, P=0.05). This wave decreased markedly with increasing heart rate (β coefficient=-0.16×10(-4) W · m(-2) · s(-2); P<0.001). After PAVR, despite a fall in basal suction wave (1.9±0.3 versus 1.1±0.1×10(-5) W · m(-2) · s(-2); P=0.02), there was an immediate improvement in coronary physiological reserve with increasing heart rate (β coefficient=0.9×10(-3) W · m(-2) · s(-2); P=0.014). CONCLUSIONS: In aortic stenosis, the coronary physiological reserve is impaired. Instead of increasing when heart rate rises, the coronary diastolic suction wave decreases. Immediately after PAVR, physiological reserve returns to a normal positive pattern. This may explain how aortic stenosis can induce anginal symptoms and their prompt relief after PAVR. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01118442.
Davies et al. (Tue,) conducted a observational in Aortic stenosis (n=11). Percutaneous aortic valve replacement (PAVR) vs. Before PAVR (baseline) was evaluated on Basal myocardial suction wave intensity (10^-5 W·m^-2·s^-2) (p=0.02). Percutaneous aortic valve replacement immediately restored coronary physiological reserve, reversing the abnormal decline in diastolic suction wave during increased heart rate (P=0.014).