Contributor: Steven Stroud
Frustrated by limited, single small center risk scores for RV failure? Kiernan and colleagues analyzed the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) to identify factors associated with RV failure following continuous flow left ventricular assist device (CF-LVAD) support.
This cohort is huge – 9,976 patients. The study group was mostly male (78.9%), >60 y/o (47.3%), ischemic cardiomyopathy (48%) and 36% were implanted as destination therapy. RV failure was defined rigorously as: 1) RVAD within 14 days of CF-LVAD implantation or 2) death following CF-LVAD (closely linked with RV failure). RVAD was required in 386 (3.9%) patients within 14 days of CF-LVAD implantation, and 222 (2%) patients died.
RVADs were more often necessary in INTERMACS patient profiles 1 (10% of implants) and 2 (4% of implants). Additional independent factors for early RVAD without and with RVAD were:
1) Narrow pulmonary artery pulse pressure (25 vs 20.5 mmHg)
2) Higher right atrial pressure (12 vs 16 mmHg)
3) Prior CABG
4) Concomitant procedure (other than tricuspid repair) during LVAD
5) Severe tricuspid regurgitation (12.7% vs 19.9%), but peri-LVAD tricuspid valve repair did not affect the RVAD requirement
6) Smaller LV end diastolic diameter (6.8 vs 6.6 cm)
7) Interventions within 48 hours of CF-LVAD: ECMO, hemodialysis
No study is perfect. This study was retrospective, lacked right heart catheterization variables (in > 20% of patients) and had incomplete qualitative echo RV function assessment (in > 50% of patients). Early vs. late RVAD placement was not distinguished in the cohort. Additionally, CF-LVAD flow type (axial vs centrifugal) was not compared.