Normal and Abnormal Relationships of Pulmonary Artery to Wedge Pressure During Exercise

Background Resting right heart catheterization can assess both left heart filling and pulmonary artery (PA) pressures to identify and classify pulmonary hypertension. Although exercise may further elucidate hemodynamic abnormalities, current pulmonary hypertension classifications do not consider the expected interrelationship between PA and left heart filling pressures. This study explored the utility of this relationship to enhance the classification of exercise hemodynamic phenotypes in pulmonary hypertension. Methods and Results Data from 36 healthy individuals (55, 50–60 years, 50% male) and 85 consecutive patients (60, 49–71 years, 48% male) with dyspnea and/or suspected pulmonary hypertension of uncertain etiology were analyzed. Right heart catheterization was performed at rest and during semiupright submaximal cycling. To classify exercise phenotypes in patients, upper 95% CIs were identified from the healthy individuals for the change from rest to exercise in mean PA pressure over cardiac output (ΔmPAP/ΔCO ≤3.2 Wood units [WU]), pulmonary artery wedge pressure over CO (ΔPAWP/ΔCO ≤2 mm Hg/L per minute), and exercise PA pulse pressure over PAWP (PP/PAWP ≤2.5). Among patients with a ΔmPAP/ΔCO ≤3.2 WU, the majority (84%) demonstrated a ΔPAWP/ΔCO ≤2 mm Hg/L per minute, yet 23% demonstrated an exercise PP/PAWP >2.5. Among patients with a ΔmPAP/ΔCO >3.2 WU, 37% had an exercise PP/PAWP >2.5 split between ΔPAWP/ΔCO groups. Patients with normal hemodynamic classification declined from 52% at rest to 36% with exercise. Conclusions The addition of PP/PAWP to classify exercise hemodynamics uncovers previously unrecognized abnormal phenotypes within each ΔmPAP/ΔCO group. Our study refines abnormal exercise hemodynamic phenotypes based on an understanding of the interrelationship between PA and left heart filling pressures.

Invasive exercise hemodynamics in patients with severe primary mitral regurgitation and preserved ejection fraction predicts future valve surgery

Background The role of invasive exercise hemodynamics in the management of asymptomatic patients with severe primary mitral regurgitation (MR) is unclear. Methods and results We compared the predictive power of parameters of invasive exercise testing for future valve surgery to guideline-defined non-invasive criteria. Maximal pulmonary capillary wedge pressure (PCWP), PCWP normalized to workload and weight (PCWL), and invasive maximal systolic pulmonary artery pressure (SPAP) were assessed in 113 asymptomatic patients with severe primary MR between 1996 and 2012. Mean age was 52±11 years, 16% were female, ejection fraction was ≥55% in all patients. During a median follow up of 4.5 years (IQR2.0; 8.3) 54 patients (48%) underwent valve surgery. In univariate analysis PCWP (P<0.001), PCWL (P<0.001), and maximal SPAP (P=0.009) were significantly associated with future mitral valve surgery. In multivariate analysis maximum PCWP and PCWL predicted future mitral valve surgery (HR 2.1 (1.44–3.10), P=0.005 and HR 1.31 (1.14–1.52), P<0.001, respectively) whereas SPAP did not. Adding maximum PCWP >25mmHg to a Cox regression model based on non-invasive guideline criteria resulted in a significant increase in the area under the curve (0.61 to 0.68, P=0.02). Conclusion In asymptomatic patients with severe primary mitral regurgitation and preserved left ventricular function invasive exercise hemodynamics improves information derived from current non-invasive guideline criteria. Figure 1 Funding Acknowledgement Type of funding source: None