Predictive Capability of Cardiopulmonary and Exercise Parameters From Day 1 to 6 Months After Acute Pulmonary...

We hypothesized that the slope of relation ventilation to carbon dioxide output (V'E/V'CO2-slope) could be predictive already during the very first days after submassive pulmonary embolism (PE) to right ventricular systolic pressure (RV_sys by echocardiography) after 6 months. We evaluated 21 hemodynamically stable patients at admittance, at days 3, 7, 90, and 180 by cardiopulmonary exercise testing and echocardiography. V'E/V'CO2-slope (48.4 ± 10.8) decreased within the first week (43.0 ± 9.8 at day 7) and normalized until follow-up at 6 months (35.0 ± 11.3; P < 10^-4), p(a-ET)CO₂ remained abnormal between days 1 and 3 (5.0 ± 3.9 to 6.7 ± 5.3 mmHg). RV_sys declined from 41.7 ± 14.3 to 26.3±13.1 mmHg (P < 10^-4) at 6 months. V'E/V'CO2-slope (r²= 0.27; P < .02) and RV_sys (r² = 0.28; P = .03) at day 7 correlated with RV_sys at 6 months. p_(a-ET)CO₂, p_(a-ET)O₂, V'D/V'T were not related to RV_sys after 6 months. RV_sys 6 months after acute PE is positively correlated with the V'E/V'CO2-slope at day 7.