Global work index correlates with established prognostic parameters of heart failure

Identification of patients with heart failure and a poor prognosis is paramount to ensure timely and adequate treatment. We investigated the relationship between the new measures of noninvasive pressure-strain analysis, such as the global work index (GWI), and established prognostic parameters of echocardiography, cardiopulmonary exercise test (CPX), and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP).

We retrospectively analyzed data of 51 patients with heart failure. Echocardiography and CPX were performed, and NT-pro-BNP was determined. Patients with a GWI < 500 mm Hg% had a mean LVEDV of 286.1 ± 100.8 mL, an LVEF of 21.3 ± 5.7%, and a stroke volume (SV) of 45.9 ± 11.6 mL, and patients with a GWI > 1000 mm Hg% had an LVEDV of 147.9 ± 39.6 mL, an LVEF of 42.6 ± 4.8%, and a SV of 70.9 ± 14.3 mL. The GWI also showed a significant correlation with peak oxygen consumption (peak VO₂ ) (r = .521; P < .001) and with NT-pro-BNP (r = .635; P < .001). Patients with a GWI of <500 mm Hg% had a significantly higher NT-pro-BNP (median 2415 pg/mL [IQR 1071, 5933]) and a lower peak VO₂ (9.5 mL/min/kg ± 2.6) compared to patients with a GWI of >1000 mm Hg% (NT-pro-BNP median 253 pg/mL [IQR 150, 549]; peak VO₂ 15.6 ± 4.2 mL/min/kg).

GWI correlates with known prognostic markers of heart failure. A GWI of <500 mm Hg% was a predictor of severely impaired ejection fraction, very low exercise capacity, and strongly elevated NT-pro-BNP, indicating a poor prognosis.