Kushwaha, Sudhir S.

Although improvement in cardiac output and hemodynamic parameters is routinely demonstrated in patients implanted with continuous-flow left ventricular assist devices (CF-LVADs), improvement in exercise capacity is inconsistently seen. Our purpose was to determine whether native cardiac factors, LVAD factors, or comorbid factors were associated with lack of improvement. Review of all patients undergoing preimplant cardiopulmonary exercise testing (CPET) and CPET on LVAD therapy at one institution was performed between 2007 and 2014 (n = 49). Comprehensive assessment of echocardiographic parameters, right heart catheterization data, medications, and comorbid illness was undertaken. There was no mean improvement in peak oxygen consumption (VO2; 11.8–12.4 ml/kg/min; p = 0.26), although exercise time (5.1 [46% predicted] to 5.8 min [56% predicted]; p = 0.02) and nadir of the ratio of minute ventilation to carbon dioxide production slope (VE/VCO2; 39–36; p = 0.001) improved. Factors most strongly associated with improvement in VO2 were Heartmate II pulsatility index (PI; R = 0.48; p = 0.001), power (R = −0.40; p = 0.009), pump flow (R = −0.40; p = 0.008), and pump speed (R = −0.32; p = 0.04). Peak heart rate (HR) was also associated with improvement in VO2 (R = 0.41; p = 0.004). Left ventricular ejection fraction (LVEF; R = 0.004; p = 0.77), right ventricular (RV) function (R = 0.22; p = 0.28), and aortic valve opening (R = 0.20; p = 0.57) were not associated with improvement in VO2. Our data suggest that less reliance on LVAD support was modestly associated with improvement in exercise capacity. Further studies should seek to determine the optimal level of device support prospectively in relation to exercise capacity.

Reversal of pulmonary hypertension has been observed in patients during a bridge to transplant with a left ventricular assist device. Total artificial heart (TAH) implant prevents subsequent right heart catheterization. Consequently, controversy exists over whether the prosthetic right ventricle improves or exacerbates pulmonary hypertension. A pulmonary artery (PA) pressure monitor was placed in two patients undergoing TAH implant, as a bridge to transplant. One patient had pulmonary hypertension at implant; the other had normal pulmonary pressures. Daily measurements were taken of systolic, diastolic, and mean PA pressures throughout support. Patient 1 received successful transplant after TAH support of 91 days. Systolic/diastolic (mean) PA pressures steadily decreased from 55/39 (28) mm Hg at implant to 29/18 (7) mm Hg currently. Patient 2 received support for 101 days before death due to abdominal ischemic complications. Pulmonary arterial pressures stayed consistent throughout this period, from 26/17 (20) mm Hg at implant to 23/13 (17) mm Hg at the time of death. These findings suggest that an implantable PA pressure monitor may be useful in optimizing hemodynamics and planning appropriate timing of transplant with TAH support.

Abstract Right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation is associated with increased morbidity and mortality, but the identification of LVAD candidates at risk for RVF remains challenging. We undertook a systematic review and meta-analysis of observational studies of risk factors associated with RVF after LVAD implant. Thirty-six studies published between 1 January 1995 and 30 April 2015, comprising 995 RVF patients out of a pooled final population of 4428 patients, were identified. Meta-analysed prevalence of post-LVAD RVF was 35%. A need for mechanical ventilation [odds ratio (OR) 2.99], or continuous renal replacement therapy (CRRT; OR 4.61, area under the curve 0.78, specificity 0.91) were the clinical variables with the highest effect size (ES) in predicting RVF. International normalized ratio [INR; standardized mean difference (SMD) 0.49] and N-terminal pro-brain natriuretic peptide (NT-proBNP) (SMD 0.52) were the biochemical markers that best discriminated between RVF and No-RVF populations, though NT-proBNP was highly heterogeneous. Right ventricular stroke work index (RVSWI) and central venous pressure (CVP) (SMD −0.58 and 0.47, respectively) were the haemodynamic measures with the highest ES in identifying patients at risk of post-LVAD RVF; CVP was particularly useful in risk stratifying patients undergoing continuous-flow LVAD implant (SMD 0.59, P < 0.001, I2 = 20.9%). Finally, pre-implant moderate to severe right ventricular (RV) dysfunction, as assessed qualitatively (OR 2.82), or a greater RV/LV diameter ratio (SMD 0.51) were the standard echocardiographic measurements with the highest ES in comparing RVF with No-RVF patients. Longitudinal systolic strain of the RV free wall had the highest ES (SMD 0.73) but also the greatest heterogeneity (I2 = 74%) and was thus only marginally significant (P = 0.05). Patients on ventilatory support or CRRT are at high risk for post-LVAD RVF, similarly to patients with slightly increased INR, high NT-proBNP or leukocytosis. High CVP, low RVSWI, an enlarged right ventricle with concomitant low RV strain also identify patients at higher risk.

Renal function improves early after left ventricular assist device (LVAD) implantation but later decline has been observed. We sought to determine the occurrence and evaluate possible causes for this decline. In 62 consecutive patients with HeartMateII LVAD with available calculated glomerular filtration rate (GFR, ml/min/1.73 m2) 1 year after implant, GFR was assessed repeatedly and possible predictors for decline from 3 to 12 months were investigated. Post-mortem renal specimens for patients supported with an LVAD were evaluated. GFR 54.5 ± 19.5 at admission increased to 66.4 ± 22.3 preoperatively and to 79.2 ± 30.1 ~1 month after implantation. Subsequently at ~3 months GFR declined to 74.7 ± 25.4, at ~6 months to 68.8 ± 23.1, and ~1 year after implant to 63.9 ± 17.7. Glomerular filtration rate at 1 year was significantly lower (p < 0.0001, p < 0.0001, p = 0.005) than GFR 1, 3, and 6 months after implant. Early rise in GFR after surgery was not associated with late decline. Shorter bypass time (β = −0.09, p = 0.048) and higher albumin 3 months after LVAD (β = 14.4, p = 0.025) were significantly associated with less later decline in GFR. Arteriosclerosis was identified in autopsy renal specimens. In conclusion, early gains in renal function after LVAD implant are not sustained in many patients. Patient, device, and operative factors may influence long-term renal function in these patients.

Background Pregnancies may result in antibodies against HLA, a risk factor for antibody-mediated rejection (AMR) and subsequent cardiac allograft vasculopathy (CAV) after heart transplantation (HTx). The aim of this study was to evaluate sex differences in the incidence of AMR events and subsequent risk of CAV among HTx recipients. Methods The study comprised 160 patients (51 [32%] women) who underwent HTx in 2008 to 2014. The cumulative effect of AMR events was calculated by AMR score (sum of myocardial biopsy grading divided by number of biopsies taken during 3 years post-HTx). Results Females had higher levels of anti-HLA I antibodies pre-HTx compared to males which was associated with a history of pregnancies, total number of children and with a higher AMR score at 6 months post-HTx (P < 0.05). Women demonstrated a significant increase in the total incidence of AMR events (27 vs. 7%, P = 0.001) and in AMR scores at 6, 12, 24 and 36 months post-HTx compared to men (P < 0.05). There were no differences in cellular rejection between the groups. A history of AMR events was associated with a significantly increased risk of severe CAV onset (hazard ratio, 7.0; 95% confidence interval, 1.5-31.5; P = 0.012). Conclusions Women are at higher risk for AMR post-HTx which subsequently increases their risk for CAV. Females recipients may benefit from closer surveillance to identify AMR at an earlier stage post-HTx, and targeted immunosuppressive therapy to attenuate the development of CAV.

As ventricular-assist devices (VADs) are increasingly employed in heart failure management, a leading cause of mortality, new literature is consistently published on less-invasive implantation techniques. Although early perioperative outcomes have been shown to be favorable with minimally invasive left thoracotomy (LT) approaches compared with conventional sternotomy (CS), studies comparing long-term outcomes are lacking. We set out to evaluate long-term follow up between LT and CS approach. In a single center, retrospective review, data on patients with similar demographic profiles were collected. HeartWare (HVAD) implantation was performed by either CS or LT. Analysis was performed on perioperative adverse outcomes, and 6 month postoperative adverse events. Primary objectives of the study included comparative outcomes of morbidity and mortality between both groups at 180 days postimplantation. Eighty-one (n = 81) bridge to transplant (BTT) patients underwent CS or LT HVAD implantation. Perioperative transfusion (p = 0.04) favored the LT cohort compared with CS, with a median of 6 units and 8 units transfused for each group, respectively. No survival difference was observed between both groups at 6 months postimplantation (p = 0.52). Clinical outcomes at an average of 6 month follow up showed no difference in adverse events, including common postoperative VAD complications such as infection and right heart failure. Miniaturization of LVAD size and improvement in technology has allowed expansion of interest in alternative surgical approaches for HVAD implantation. For BTT patients, no difference in early outcome was observed 6 months after implantation using a left LT versus CS technique.