Survival analysis and post-operative complications after ventricular assist device implantation, prognostic value of INTERMACS scale
Background: Ventricular assist devices (VADs) have proven to be effective in improving survival and quality of life in patients with refractory heart failure. However, postoperative outcomes depend on a variety of preoperative parameters. The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) scale is a useful classification to categorize advanced heart failure patients and predict outcome before VAD implantation. This single center study evaluates retrospectively preoperative patients’ profiles, clinical outcomes, postoperative complications, mortality and predictors of total mortality in patients who underwent left ventricular assist device (LVAD) implantation in our center taking into account preoperative INTERMACS levels aiming at anticipation of postoperative complications and their temporality and optimization of preoperative strategies. Methods: Our Study focused on 104 adult patients who underwent LVAD implantation between August 2010 and March 2015 in West German Heart- and Vascular Center, University Hospital Essen. All device implants were 3rd generation HeartWare HVAD. INTERMACS profiles were as follow: level 1 in 27 patients, level 2 in 20 patients, level 3 in 27 patients, level 4 in 25 patients, level 5 in 4 patients and level 6 in 1 patients respectively. Patients were divided according to clinical similarity into 3 groups: group A included 27 patients at INTERMACS level 1. Group B included 47 patients at INTERMACS level 2/3 and group C included 30 patients at INTERMACS Level 4/5/6. We retrospectively analyzed preoperative demographic, clinical, hemodynamic, laboratory and echocardiographic parameters. Furthermore, we also sought to characterize postoperative complications by exploring not only frequency of events and their relation to preoperative INTERMCAS profiles but also the timing of complications. Lastly, we evaluated mortality in all groups. Results: The most common postoperative complications were sepsis, right ventricular failure followed by respiratory failure. Renal failure was the most common complication within 1 week after the operation, whereas stroke was most common late complication occurring after 6 months after the implantation. Group A had a significant higher incidence of postoperative complications in comparison to the other groups. Total mortality was significantly higher in group A patients, whereas there was no significant difference between group B and C. Preoperative predictors of postoperative mortality were high central venous pressure, high systolic pulmonary artery pressure, high serum blood urea nitrogen, high serum procalcitonin and presence of metabolic acidosis. Conclusion: The severity of advanced heart failure as determined by the pre-operative INTERMACS profile influences the postoperative outcome of patients receiving LVAD in our single center study. Optimization of preoperative volume status, preload and right heart function as well as management of preoperative sepsis are recommended to lower mortality in such patients. The results suggest that patient selection for LVAD should focus on identifying advanced heart failure patients before they reach the stage of critical cardiogenic shock.