Study results suggest less invasive HeartMate 3 implantation is a safe and effective approach for obese patients

BACKGROUND

Historically, obesity was considered a relative contraindication to left ventricular assist device (LVAD) implantation with less invasive surgery (LIS). The present study aimed to compare the outcomes of obese patients who underwent LVAD implantation through LIS with those who received full sternotomy (FS) implantation.

METHODS

We retrospectively reviewed all patients implanted with HeartMate 3 LVAD in our institution between September 2015 and June 2020. Obese patients (BMI ≥ 30 kg/m²) were included and dichotomized based on surgical approach into the FS or LIS cohort.

RESULTS

Of 231 implanted patients, 107 (46%) were obese and included in the study. FS was performed in 26 (24%) patients and LIS approach in 81 (76%) patients. Preoperative patient characteristics were similar between the cohorts. Postoperatively, patients in LIS cohort had less bleeding (p = 0.029), fewer transfusions (p = 0.042), shorter duration of inotropic support (p = 0.049), and decreased incidence of severe RV failure (11.1% vs 30.8%, p = 0.028). Survival to discharge for the obese population was 87.5% overall and did not differ based on an approach (91.4% LIS vs 76.9% FS, p = 0.079). More LIS patients were discharged home (60.0% vs 82.4%, p = 0.041) rather than to rehabilitation center.

CONCLUSION

Our results showed that the LIS approach in obese patients is associated with fewer postoperative complications and a trend towards better short-term survival. These results suggest that less invasive LVAD implantation is a safe and effective approach for obese patients. Future prospective randomized trials are required to substantiate these results.

Positron emission tomography objective parameters for assessment of left ventricular assist device infection using 18F-FDG PET/CT

Left ventricular assist device (LVAD) is a life-saving therapy, but it poses a substantial infection risk. Current evaluation of LVAD infection with ¹⁸F-FDG PET/CT is predominately subjective. We present qualitative and semi-quantitative ¹⁸F-FDG PET/CT parameters for early detection of LVAD infection and site localization. We retrospectively reviewed all 25 LVAD patients at our institution who had undergone ¹⁸F-FDG PET/CT imaging between 2014 and 2018. LVADs were subdivided into five assessed regions: driveline exit site, subcutaneous driveline, LVAD pump, LVAD inflow, and LVAD outflow cannulae. Ultimate diagnosis of LVAD infection was determined by a multidisciplinary primary care team. Qualitative and semi-quantitative analysis of PET/CT data were performed, including calculation of the standardized uptake value maximum, mean, and peak (SUV_max, SUV_mean, and SUV_peak, respectively), as well as metabolic tumor volume (MTV), and total lesion glycolysis (TLG). A total of 14 patients presented with symptoms of infection, and LVAD infection was ultimately diagnosed in 19 of the 25 cases. All cases were correctly identified on ¹⁸F-FDG PET/CT with no false positive and no false negative cases, corresponding to a sensitivity and specificity of 100%. The mean SUV_max range at noninfected sites was 2.5-3.4, and the range was 5.7-8.1 at infected sites, resulting in a significant difference (P < 0.01) at all LVAD regions. ¹⁸F-FDG PET/CT is a useful adjunctive tool for assessment of LVAD infection and infection localization, which is crucial for clinical management. A cut-off SUV_max 5 is recommended to help diagnose LVAD infection.

Durability of left ventricular assist devices: Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) 2006 to 2011

OBJECTIVES

The present study compared the interval until device exchange or death from pump-related failure in patients with pulsatile versus continuous flow left ventricular assist devices.

METHODS

Data from Interagency Registry for Mechanically Assisted Circulatory Support (June 23, 2006, to March 31, 2011) compared the durability of implanted pulsatile and continuous flow left ventricular assist devices. The durability issues included pump replacement for infection, thrombosis-hemolysis, driveline failure, or pump drive unit failure, and death from driveline or pump drive unit failure.

RESULTS

A total of 3302 left ventricular assist devices were implanted (486 pulsatile, 2816 continuous flow) and 98 pump exchanges or deaths from durability issues (46 pulsatile, 52 continuous flow; 3% of implants). The interval to device issue was greater for the continuous flow than for the pulsatile devices (P < .001). A comparisons of the causes for pump exchange or pump-related death showed (1) greater freedom from pump failure in the continuous flow compared with the pulsatile left ventricular assist devices (10 events/2816 continuous flow implants vs 39 events/486 pulsatile implants; P < .0001); (2) similar exchange or pump-related death for driveline failure (1/486 pulsatile vs 7/2816 continuous flow; P = .82); (3) similar exchange or pump-related death for thrombosis-hemolysis (2/486 pulsatile vs 28/2816 continuous flow; P = .25); and (4) fewer exchanges or pump-related deaths from infection in continuous flow left ventricular assist devices (4/486 pulsatile vs 7/2816 continuous flow; P = .034). Competing outcomes analysis corroborated this finding, with 54% of continuous flow versus 23% of pulsatile patients alive and receiving support at 12 months after implantation.

CONCLUSIONS

The Analysis of Interagency Registry for Mechanically Assisted Circulatory Support data showed greater durability for continuous flow than for pulsatile left ventricular assist devices. Even longer durations of support can be expected if pump durability continues to improve.