Strong and independent prognostic value of peak circulatory power in adults with congenital heart disease

Background: The identification of patients with adult congenital heart disease (ACHD) who are at higher risk of death is challenging. Peak circulatory power (CircP; expressed as peak exercise oxygen uptake multiplied for peak mean arterial blood pressure) is a strong predictor of death in adults with acquired heart disease. We sought to establish the distribution and the prognostic value of peak CircP across a wide spectrum of patients with ACHD. Methods: Four hundred thirty-two consecutive patients with ACHD of varying diagnosis underwent cardiopulmonary exercise testing at a single laboratory between 1996 and 2005. Patient age was 32 ± 10 years. Results: A gradual variation in peak CircP was found across the spectrum of congenital heart defects (P <.0001 at analysis of variance). Reduced peak CircP values were associated with the presence of heart failure symptoms (P <.0001), absence of sinus rhythm (P = .010), and use of antiarrhythmic medications (P = .0013). At a follow-up of 4.4 ± 2.4 years, 23 patients (5.3%) had died. Peak CircP was a strong predictor of mortality when univariate analysis was used and the strongest independent predictor of mortality among exercise parameters. A peak CircP ≤1476 mm Hg mlO₂ min^-1 kg^-2 was associated with a 15.4-fold increase in the 4-year risk of death. Conclusions: Peak CircP is abnormal across the spectrum of ACHD. Peak CircP appears as the strongest predictor of adverse outcome in ACHD.