Prognostic Importance of Pulmonary Artery Pulsatility Index and Right Ventricular Stroke Work Index in End-Stage Heart Failure Patients

Background: Right ventricular (RV) failure is an important cause of morbidity and mortality in patients with left ventricular (LV) end-stage heart failure (ESHF). Pulmonary artery pulsatility index (PAPi) and right ventricular stroke work index (RVSWI) are invasive parameters related to RV function. This study aimed to investigate the prognostic impact of PAPi and RVSWI in these patients. Methods and Results: In this study, 416 patients with ESHF were included. The adverse cardiac event (ACE) was defined as left ventricular assist device (LVAD) implantation, urgent heart transplantation, or cardiac mortality. There were 218 ACE cases and 198 non-ACE cases over a median follow-up of 503.50 days. Patients with ACE had lower PAPi and similar RVSWI compared to those without ACE (3.1±1.9 vs. 3.7±2.3, P=0.003 and 7.3±4.9 vs. 6.9±4.4, P=0.422, respectively). According to the results of multivariate analysis, while PAPi (from 2 to 5.65) was associated with ACE, RVSWI (from 3.62 to 9.75) was not associated with ACE (HR: 0.75, 95% CI (0.55-0.95), P=0.031; HR: 0.79, 95% CI: (0.58-1.09), P=0.081, , respectively). Survival analysis revealed that PAPi ≤2.56 was associated with a higher ACE risk compared to PAPi >2.56 (HR: 1.46, 95% CI: 1.11-1.92, P=0.006). PAPi ≤2.56 could predict ACE with 56.7% sensitivity and 51.3% specificity at one year. Furthermore, the association between RVSWI and ACE was nonlinear (J-curve pattern). Low and high values seem to be associated with higher ACE risk compared to intermediate values. Conclusion: The low PAPi was an independent risk for ACE and it had a linear association with it. However, RVSWI seems to be have a nonlinear association with ACE (J-curve pattern).

The Prognostic Role of Right Ventricular Stroke Work Index during Liver Transplantation

Right heart-associated hemodynamic parameters including intraoperative pulmonary vascular resistance (PVR) were reported to be associated with patient survival after liver transplantation. We investigated whether intraoperative stroke work indexes of both ventricles could have a better prognostic value than PVR. We reviewed 683 cases at a tertiary care academic medical center. We collected intraoperative variables of baseline central venous pressure, baseline right ventricle end-diastolic volume, mixed venous oxygen saturation, intraoperative PVR and right and left ventricular stroke work indexes. Time-weighted means or area under the curve of intraoperative right and left ventricular stroke work indexes were calculated as exposure variables. One-year all-cause mortality or graft failure was our primary outcome. Cox proportional hazard regression analysis was performed to evaluate the association between exposure variables and one-year all-cause mortality or graft failure. Kaplan–Meier survival curve analysis of our primary outcome was performed for different time-weighted mean ventricular stroke work index groups. Cubic spline curve analysis was performed to evaluate the linear relationship between our exposure variables and primary outcome. Time-weighted mean right ventricular stroke work index was significantly associated with one-year all-cause mortality or graft failure (hazard ratio 1.21, 95% confidence interval (CI) 1.12–1.36, p < 0.001). However, there was no significant association between time-weighted mean left ventricular stroke work index, time-weighted mean PVR, PVR at the end of surgery and one-year mortality. Area under the curve of right ventricular stroke work index was also significantly associated with one-year mortality or graft failure (hazard ratio 1.24, 95% CI 1.15–1.37, p < 0.001). Kaplan–Meier survival curve analysis showed a significant difference in the survival between different mean right ventricular stroke work index groups (Log-rank test: p = 0.002). Cubic spline function curve showed the gradual increase in the risk of mortality with a positive slope with time-weighted mean right ventricular stroke work index. In conclusion, intraoperative elevated right ventricular stroke work index was significantly associated with poor patient or graft survival after liver transplantation. Intraoperative right ventricular stroke work index could be an intraoperative hemodynamic goal and prognostic marker for mortality after liver transplantation.

Noninvasive Echocardiographic Left Ventricular Stroke Work Index Predicts Mortality in Cardiac Intensive Care Unit Patients

Background: Reduced left ventricular stroke work index (LVSWI) has been associated with adverse outcomes in several populations of patients with chronic heart disease, but no prior studies have examined this metric in cardiac intensive care unit (CICU) patients. We sought to determine whether a low LVSWI, as measured noninvasively using transthoracic echocardiography, is associated with higher mortality in CICU patients. Methods: Using a database of unique Mayo Clinic CICU admissions from 2007 to 2018, we identified patients with LVSWI measured by transthoracic echocardiography within 1 day of CICU admission. Hospital mortality was analyzed using multivariable logistic regression, and 1-year mortality was analyzed using multivariable Cox proportional-hazards analysis, adjusted for left ventricular ejection fraction and known predictors of hospital mortality. Results: We included 4536 patients with a mean age of 68±14 years (36% women). Admission diagnoses (not mutually exclusive) included acute coronary syndrome in 62%, heart failure in 46%, and cardiogenic shock in 11%. The mean LVSWI was 38±14 g×min/m 2 , and in-hospital mortality occurred in 6% of patients. LVSWI had better discrimination for hospital mortality than left ventricular ejection fraction ( P <0.001 by De Long test). Higher LVSWI was associated with lower in-hospital mortality (adjusted odds ratio, 0.72 per 10 g×min/m 2 higher [95% CI, 0.61–0.84]; P <0.001) and lower 1-year mortality (adjusted hazard ratio, 0.812 per 1 g×min/m 2 higher [95% CI, 0.759–0.868]; P <0.001). Stepwise decreases in hospital and 1-year mortality were observed with higher LVSWI. Conclusions: Low LVSWI, reflecting poor left ventricular systolic and diastolic performance, is associated with increased short-term and long-term mortality among CICU patients. This emphasizes the importance of Doppler transthoracic echocardiography as a predictor of outcomes among critically ill patients. Further study is required to determine whether early interventions to optimize LVSWI can improve outcomes in the CICU setting.