Background and aim of the study: Pulmonary hypertension (PH) is commonly described as a risk factor in cardiac surgery; however, the effect of a low left ventricular ejection fraction (LVEF) on PH has not been assessed. Hence, the study aim was to determine whether PH increases operative mortality and survival outcome in patients with a low LVEF.
Methods: Between January 2001 and September 2009, a total of 845 consecutive patients with LVEF < 40% was enrolled into the study. Among these patients, 444 had a pulmonary pressure < 40 mmHg (NPH group), while in 401 patients the pulmonary pressure was > or = 40 mmHg.
Results: Preoperatively, the PH patients were older (p < 0.001), had a lower LVEF (p = 0.001), and had a higher logistic EuroSCORE (p < 0.001) and serum creatinine level (p < 0.026) when compared to NPH patients. The PH patients showed a greater tendency to develop postoperative complications (p < 0.001). After adjusting by propensity score, the in-hospital mortality was significantly higher among PH patients (p < 0.001), while multivariate logistic regressions revealed PH as an independent predictor for in-hospital mortality (p = 0.036). The 12-, 36-, and 60-month follow up mortality rates were significantly higher in the PH group. By using a Cox logistic regression model, PH was shown to be an independent predictor for follow up mortality (p = 0.035).
Conclusion: Pulmonary hypertension increased the morbidity and mortality in patients with a low LVEF who were undergoing cardiac surgery. Future studies may identify subgroups that may benefit from a preoperative optimization of PH and/or intra- and postoperative therapies directed at minimizing the effects of the condition.