Predicting right ventricular failure in the modern, continuous flow left ventricular assist device era

Abstract

Background: In the era of destination continuous flow left ventricular assist devices (LVAD), the decision of whether a patient will tolerate isolated LVAD support or will need biventricular support (BIVAD) can be challenging. Incorrect decision making with delayed right ventricular (RV) assist device implantation results in increased morbidity and mortality. Continuous flow LVADs have been shown to decrease pulmonary hypertension and improve RV function. We undertook this study to determine predictors in the continuous flow LVAD era that identify patients who are candidates for isolated LVAD therapy as opposed to biventricular support.

Methods: We reviewed demographic, hemodynamic, laboratory, and echocardiographic variables for 218 patients who underwent VAD implant from 2003 through 2011 (LVAD=167, BIVAD=51), during the era of continuous flow LVADs.

Results: Fifty preoperative risk factors were compared between patients who were successfully managed with an LVAD and those who required a BIVAD. Seventeen variables demonstrated statistical significance by univariate analysis. Multivariable logistic regression analysis identified central venous pressure>15 mmHg (OR 2.0, "C"), severe RV dysfunction (OR 3.7, "R"), preoperative intubation (OR 4.3, "I"), severe tricuspid regurgitation (OR 4.1, "T"), heart rate>100 (OR 2.0, Tachycardia-"T")-CRITT as the major criteria predictive of the need for biventricular support. Utilizing these data, a highly sensitive and easy to use risk score for determining RV failure was generated that outperformed other established risk stratification tools.

Conclusions: We present a preoperative risk calculator to determine suitability of a patient for isolated LVAD support in the current continuous flow ventricular assist device era.

Keywords: 27.

Fig 1

Distribution of CRITT scores for the left ventricular assist device (LVAD) cohort (blue bars) and biventricular assist device (BIVAD) cohort (green bars). (CRITT = central venous pressure >15 mm Hg [C]; severe right ventricular dysfunction [R]; preoperative mechanical ventilation/intubation [I]; severe tricuspid regurgitation [T]; and tachycardia [T].)

Fig 2

Receiver-operating characteristic curves of the CRITT score (solid blue line) as well as other univariate and multivariable predictors of right ventricular failure. Refer to Table 8 for the area under the curve for each receiver-operating characteristic curve. Reference line is in red (null hypothesis); Matthews et al. [10], solid green line; central venous pressure, solid yellow line; mean pulmonary artery pressure, solid purple line; alanine aminotransferase, dashed blue line; total bilirubin, dashed yellow line; and creatinine, dashed aqua line. (CRITT = central venous pressure >15 mm Hg [C]; severe right ventricular dysfunction [R]; preoperative mechanical ventilation/intubation [I]; severe tricuspid regurgitation [T]; and tachycardia [T].) (ALT = alanine transaminase; CVP = central venous pressure; PAP = pulmonary artery pressure.)