Echocardiographic Predictors of Adverse Short-term Outcomes after Heart Surgery in Patients with Mitral Regurgitation and Pulmonary Hypertension

Abstract

<p><b>Background:</b> Pulmonary hypertension (PH) is a frequent occurrence and a negative prognostic indicator in patients with mitral regurgitation. Preoperative PH causes higher early and late mortality rates after heart surgery, adverse cardiac events, and postoperative systolic dysfunction in the left ventricle (LV).</p><p><b>Methods:</b> The research consisted of a retrospective study of a group of 171 consecutive patients with mitral regurgitation and preoperative PH who had undergone mitral valve surgery between January 2008 and October 2011. The PH diagnosis was based on echocardiographic evidence (systolic pulmonary artery pressure [sPAP] >35 mm Hg). The echocardiographic examination included assessment of the following: LV volume, LV ejection fraction (LVEF), sPAP, right ventricular end-diastolic diameter, right atrium area indexed to the body surface area, the ratio of the pulmonary acceleration time to the pulmonary ejection time (PAT/PET), tricuspid annular plane systolic excursion (TAPSE), determination of the severity of the associated tricuspid regurgitation, and presence of pericardial fluid. Surgical procedures consisted of mitral valve repair in 55% of the cases and mitral valve replacement in the remaining 45%. Concomitant coronary artery bypass grafting (CABG) surgery was carried out in 52 patients (30.41%), and De Vega tricuspid annuloplasty was performed in 29 patients (16.95%). The primary end point was perioperative mortality. The secondary end points included the following: pericardial, pleural, hepatic, or renal complications; the need for a new surgical procedure; postoperative mechanical ventilation >24 hours; length of stay in the intensive care unit; duration of postoperative inotropic support; need for an intra-aortic balloon pump; and need for pulmonary vasodilator drugs.</p><p><b>Results:</b> The mortality rate was 2.34%. In the univariate analysis, the clinical and echocardiographic parameters associated with mortality were preoperative New York Heart Association (NYHA) class IV, the PAT/PET ratio, TAPSE, the indexed area of the right atrium, and concomitant CABG surgery. In the multivariate analysis, the indexed area of the right atrium and concomitant CABG surgery remained statistically significant. The multivariate analysis also showed the indexed area of the right atrium, LVEF, presence of pericardial fluid, preoperative NYHA class, and concomitant CABG surgery as statistically significant for the secondary end point. The receiver operating characteristic (ROC) curves identified an sPAP value >65 mm Hg to have the highest specificity and sensitivity for the risk of perioperative death in mitral regurgitation patients (area under the ROC curve [AUC], 0.782; <i>P</i> < .001) and identified an sPAP value of 60 mm Hg as the secondary end point (AUC, 0.82; <i>P</i> < .001). Severe PH (sPAP >60 mm Hg) is associated with a significant increase in the mortality rate; a longer stay in the intensive care unit; a mechanical ventilation duration >24 hours; lengthy inotropic support; renal, hepatic, and pericardial complications; and a need for endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and/or prostanoids, both in the general group and in patients with preserved systolic functioning of the left ventricle.</p><p><b>Conclusions:</b> PH is a strong short-term negative prognostic factor for patients with mitral regurgitation. The surgical procedure should be performed in the early stages of PH. Echocardiographic examination has useful, simple, and reproducible tools for classifying operative risks. An ischemic etiology and a need for concomitant CABG surgery are additional risk factors for patients with mitral regurgitation and PH.</p>