Am J Physiol Heart Circ Physiol. 2026 Feb 9. doi: 10.1152/ajpheart.00669.2025. Online ahead of print.
ABSTRACT
In patients with aortic valve stenosis (AS), the pathophysiological abnormalities involved in the transition to heart failure are unclear. As chronic heart failure progresses, the ratio between myocardial stroke work and oxygen consumption, i.e. myocardial external efficiency (MEE), steadily deteriorates. However, in patients with AS, it is unknown whether changes in MEE are involved in disease progression. We investigated changes in MEE and if MEE was associated with long-term prognosis in patients with AS. Ten healthy controls and 38 patients with moderate-severe AS and preserved left ventricular ejection fraction ≥50% were included in the study. To evaluate MEE, we used serial 11C-acetate positron emission tomography, cardiovascular magnetic resonance imaging and echocardiography, with a median follow-up period of 2.8 years. Furthermore, we conducted a long-term follow-up for a median of 5.2 years to detect cardiac events and related them to MEE. In patients with AS, MEE increased during follow-up from 25.2% (95% CI: 24.0 to 26.5%) to 29.5% (95% CI: 27.3 to 31.8%; p=0.001) and was higher than in healthy volunteers, 19.9% (18.1 to 21.8; p<0.001). Patients who experienced a cardiac event during long-term follow-up (n=24, 63%) had higher baseline MEE, 26.5% (95% CI: 24.6 to 28.4%), than event-free patients, 23.3% (95% CI: 22.2 to 24.3%; p=0.004). In asymptomatic patients with AS, MEE increased over time and high baseline MEE predicted a poor prognosis. Thus, the myocardium displayed an inherent capacity to improve the coupling between oxidative metabolism and contractile function in response to pressure overload.
PMID:41661147 | DOI:10.1152/ajpheart.00669.2025