Relationship between renal function and left ventricular assist device use.

BACKGROUND: Poor renal function may affect outcomes after left ventricular assist device (LVAD) placement. Conversely, LVADs may optimize circulation and improve renal function. METHODS: To assess the relationship between renal function and LVAD use, changes in creatinine clearances (CrCl, in mL/min) were assessed retrospectively in 220 patients who underwent LVAD placement. These patients were also divided into four groups based on CrCl quartiles (< 47, 48-68, 69-95, and > 95) and compared for outcomes post-LVAD placement. RESULTS: Eighty-four patients died on LVAD support. Survival on LVAD was worse for patients with the worst baseline CrCl (42%, 52%, 63%, and 79% for 6 month and 26%, 34%, 47%, and 66% for 12 month survival for quartiles 1-4; both p < 0.01 for trend). Adjusting for other covariates, patients in the lowest CrCl quartile were at a higher risk of dying postimplant (odds ratio 1.95, 95% confidence interval 1.14-3.63). Paired sample analysis showed the following changes in CrCl: preoperative to week 1, 77.0 +/- 46.6 to 92.1 +/- 51.1 (p < 0.01; n = 202), week 1 to 2, 89.4 +/- 49.2 to 95.2 +/- 52.4 (p = 0.01, n = 171), week 2 to 3, 107.5 +/- 58.1 to 113.7 +/- 66.1 (p = 0.16, n = 74), and week 3 to 4, 111.1 +/- 56.6 to 110.5 +/- 56.8 (p = 0.87, n = 60). For the 60 patients with baseline CrCl less than 50, CrCl increased from 36.7 +/- 9.2 to 60.1 +/- 35.5 (p < 0.01; n = 55 pairs) from preimplant to week 1. In 37 of these patients (62%) on intraaortic balloon pump support preimplant, CrCl increased from 38.4 +/- 8.2 to 67.9 +/- 40.3 mL/minute (p < 0.01) during week 1 postimplant. Recovery of renal function to CrCl greater than 50 was associated with a trend towards better 30-day survival (84% vs 66%, p = 0.09). CONCLUSIONS: Baseline poor renal function is associated with worse outcomes after LVAD implantation. However, renal function improves substantially and rapidly in post-LVAD survivors and is associated with improved outcomes. These data underscore the importance of careful patient selection for LVAD therapy.

Diabetes and outcomes after left ventricular assist device placement.

BACKGROUND: Patients with diabetes have poorer outcomes after surgery in general. In this study, we assess the impact of diabetes on outcomes after left ventricular assist devices (LVAD) placement. METHODS AND RESULTS: Data on 222 patients (57 diabetics) who underwent Novacor LVAD placement between 1996 and 2003 were compared for outcomes among patients who did and did not have diabetes. Significant differences between the diabetics versus nondiabetics included age (56 +/- 8 versus 49 +/- 1 years, P < .01), ischemic heart failure etiology (61% versus 44%, P = .04), history of hypertension (56% versus 30%, P < .01), thoracotomy (42% versus 30%, P = .08), stroke (14% versus 5%, P = .03), and body weight (86 +/- 16 kg versus 80 +/- 17 kg, P = .03), respectively. Eighty-four patients died on LVAD support, 28 of whom were diabetic. Thirty, 180, and 365-day survival for diabetic versus nondiabetic patients was: 76.6%, 45.6%, and 30.4% for diabetics and 86.7%, 62.4%, and 47.1% for nondiabetics (P = .02 for 180 and 365-day morality). After controlling for other variables, patients with diabetes were at a higher risk of mortality (OR 1.76, 95%CI 1.05-2.94). No significant difference in survival was noted between insulin-dependent versus non-insulin-dependent diabetics. CONCLUSION: Patients with diabetes are at a higher risk of mortality after LVAD implantation.

Pre-transplant reversible pulmonary hypertension predicts higher risk for mortality after cardiac transplantation.

BACKGROUND: Pre-transplant fixed pulmonary hypertension is associated with higher post-transplant mortality. In this study, we assessed the significance of pre-transplant reversible pulmonary hypertension in patients undergoing cardiac transplantation. METHODS: Overall, we studied 182 patients with baseline normal pulmonary pressures or reversible pulmonary hypertension, defined as a decrease in pulmonary vascular resistance (PVR) to < or =2.5 Wood units (WU), who underwent cardiac transplantation. Multiple recipient and donor characteristics were assessed to identify independent predictors of mortality. RESULTS: The average duration of follow-up was 42 +/- 28 months. Forty patients (22%) died during the follow-up period. Baseline hemodynamics for alive vs dead patients were as follows: pulmonary artery systolic (PAS) 42 +/- 15 vs 52 +/- 15 mm Hg; PA diastolic 21 +/- 9 vs 25 +/- 9 mm Hg; PA mean 28 +/- 11 vs 35 +/- 10 mm Hg; transpulmonary gradient (TPG) 9 +/- 4 vs 11 +/- 7 mm Hg (all p < 0.05); total pulmonary resistance 7.7 +/- 4.8 vs 8.8 +/- 3.2 WU (p = 0.08); and PVR 2.3 +/- 1.5 vs 2.9 +/- 1.6 WU (p = 0.06). In an unadjusted analysis, patients with PAS >50 mm Hg had a higher risk of death (odds ratio [OR] 5.96, 95% confidence interval [CI] 1.46 to 19.84 as compared with PAS < or =30 mm Hg). There was no significant difference in survival among patients with baseline PVR <2.5, 2.5 to 4.0 or >4.0 WU, but patients with TPG > or =16 had a higher risk of mortality (OR 4.93, 95% CI 1.84 to 13.17). PAS pressure was an independent predictor of mortality (OR 1.04, 95% CI 1.02 to 1.06). Recipient body mass index, history of sternotomy; and donor ischemic time were the other independent predictors of mortality. CONCLUSION: Pre-transplant pulmonary hypertension, even when reversible to a PVR of < or =2.5 WU, is associated with a higher mortality post-transplant.

Body mass index and outcomes after left ventricular assist device placement.

BACKGROUND: Although extremes of body mass index (BMI) are associated with decreased survival after cardiac transplantation, its association with outcomes after left ventricular assist device (LVAD) implantation is not known. This issue is especially important as LVADs are now approved as destination therapy for advanced heart failure patients who are not transplant candidates. In this study, we assess the association between BMI and outcomes after LVAD implantation. METHODS: A total of 222 patients who underwent LVAD placement (190 bridge-to-transplant [BTT] and 32 destination therapy) were divided into four groups based on BMI (kg/m2) quartiles (group 1, <22.9; group 2, 22.9 to 26.3; group 3, 26.4 to 29.4; and group 4, >29.4) and were compared for outcomes. RESULTS: Eighty-four patients died on LVAD support. Six- and 12-month survival on LVAD for the four groups was 35%, 60%, 65%, and 73%, and 26%, 34%, 50%, and 66% (both p < 0.01), respectively. Similar trends were seen for the composite endpoint of survival on LVAD and within 30 days posttransplant among BTT patients. Infectious, neurological, respiratory, or bleeding complications were not related to BMI. Patients with higher BMI tended to have a greater risk of reoperations (43%, 49%, 53%, and 61%, p = 0.06) and renal complications (16%, 33% 23%, 43%, p = 0.03). Age and history of thoracotomy were independently associated with mortality whereas higher BMI was not. Survival was worst for patients with lowest BMI. CONCLUSIONS: Higher BMI did not adversely affect survival after LVAD implantation and therefore relative obesity should not be considered a contraindication for LVAD placement. Further work is needed to understand and manage risks for low BMI patients.

Left ventricular assist device implantation via left thoracotomy: alternative to repeat sternotomy.

Repeat sternotomy for left ventricular assist device insertion may result in injury to the right heart or patent coronary grafts, complicating intraoperative and postoperative management. In 4 critically ill patients, left thoracotomy was used as an alternative to repeat sternotomy. Anastomosis of the outflow conduit to the descending thoracic aorta provided satisfactory hemodynamic support.