Background: Decreased left ventricle ejection fraction (LVEF) is a predictor of poor late outcome in patients with mitral regurgitation (MR). The relationship between pre-operative forward stroke volume (SV) and right heart parameters and perioperative outcome in patients with MR has been little studied.
Methods: Forty patients with severe organic MR, unsuitable for mitral valve repair, who underwent mitral valve replacement (MVR) were included in the study (50% men, average age 61 +/- 9 years). Exclusion criteria were: aortic valve disease, coronary artery disease, rethoracotomy, stroke, infection or significant perioperative bleeding. Pre-operative detailed echocardiographic examination was performed. The end-point was post-operative prolonged intensive care unit (ICU) stay of more than three days because of the need for inotropic support.
Results: Pre-operative NYHA class was 2.6 +/- 0.4, mean right ventricular end-diastolic diameter (RVEDD) was 28.7 +/- 4 mm, TAPSE was 20 +/- 4 mm, mean right ventricular systolic pressure (RVSP) was 38 +/- 13 mm Hg, left ventricular end-systolic diameter was 43.5 +/- 11 mm, left ventricular end-diastolic diameter was 60 +/- 11 mm, left ventricular end-diastolic volume (Simpson) was 155 +/- 47 mL, LVEF was 55 +/- 11%, mean regurgitation fraction was 58% and forward SV (measured by Doppler) was 35 +/- +/- 11 mL. All patients survived the operation. Mean ICU stay was 3.2 +/- 2.9 days (range 1-10 days), mean TISS-28 was 623 +/- 293 and mean NEMS 151 +/- 85. By univariate analysis, ICU stay was significantly longer in patients in higher pre-operative NYHA (p = 0.04), lower LVEF (p = 0.01), lower forward SV (p = 0.001) higher RF (p = 0.01), pre-operative right ventricular dilatation (p = 0.04), higher RVSP (p = 0.006) and right ventricular dysfunction (p = 0.04). By multivariate analysis, forward SV (p = 0.002, b = -0.45) and RVEDD (p = 0.02, b = 0.31) were independent predictors for prolonged ICU stay.
Conclusions: Pre-operative forward stroke volume and right ventricle size are predictors of the perioperative hemodynamic status in patients with mitral regurgitation undergoing MVR.