Peak Circulatory Power Is A Strong Prognostic Factor In Heart Failure With Preserved Ejection Fraction

Abstract

<h3>Objectives</h3> Cardiopulmonary exercise testing (CPET) is the gold standard for assessing functional capacity and estimating prognosis in chronic heart failure (CHF). Peak circulatory power (CP) defined as the product of peak oxygen uptake (VO₂ peak) and peak exercise systolic blood pressure (SBP) was originally introduced by Cohen-Solal et al (2002) and eventually evaluated as a prognostic index in systolic CHF, congenital heart disease and idiopathic pulmonary arterial hypertension. The aim of this study was to confirm prognostic value of peak CP in HF with preserved ejection fraction (HFpEF). <h3>Methods</h3> We retrospectively analyzed the subgroup of 50 patients with HFpEF, NYHA classes II-III (17 female, mean age 64,8±11,6 years) previously enrolled in the prospective observational study. All patients received optimal medical treatment. At baseline the patients underwent comprehensive investigation including CPET. Peak CP was assessed as the product of VO₂ peak and peak SBP. Average follow-up period amounted 35 months. Cardiovascular mortality was considered the primary end-point. <h3>Results</h3> Cardiovascular mortality amounted 32% (n=16). ROC-analysis demonstrated significant independent predictive value of peak CP for cardiovascular mortality (AUC=0,741; 95% CI=0,597 to 0,854; p=0,0025). According to Youden index (J = sensitivity + specificity - 1) the patients were subsequently dichotomized by peak CP of 1600 as a cut-off point (sensitivity = 56%, specificity=91%). Kaplan-Meier analysis confirmed unfavorable prognosis in patients with peak CP ≤ 1600 (Log rank chi square = 8,3; p = 0,004). <h3>Conclusion</h3> Peak circulatory power (CP) combining VO₂ peak and peak exercise systolic blood pressure demonstrates significant prognostic value in HFpEF. Low peak CP reflecting poor cardiac power indicates unfavorable prognosis in terms of cardiovascular mortality and may be used as an independent non-invasive marker for long-term risk stratification in HFpEF patients.