Hypotension on cardiopulmonary stress test predicts 90 day mortality after LVAD implantation in INTERMACS 3-6 patients

AIMS

Cardiopulmonary stress test (CPX) is routinely performed when evaluating patient candidacy for left ventricular assist device (LVAD) implantation. The predictive value of hypotensive systolic blood pressure (SBP) response during CPX on clinical outcomes is unknown. This study aims to determine the effect of hypotensive SBP response during to clinical outcomes among patients who underwent LVAD implantation.

METHODS AND RESULTS

This was a retrospective single center study enrolling consecutive patients implanted with a continuous flow LVAD between 2011 and 2022. Hypotensive SBP response was defined as peak exercise SBP below the resting value. Multivariable Cox-regression analysis was performed to evaluate the relationship between hypotensive SBP response and all-cause mortality within 30 and 90 days of LVAD implantation. A subgroup analysis was performed for patients implanted with a HeartMate III (HM III) device. Four hundred thirty-two patients underwent LVAD implantation during the pre-defined period and 156 with INTERMACS profiles 3-6 met our inclusion criteria. The median age was 63 years (IQR 54-69), and 52% had ischaemic cardiomyopathy. Hypotensive SBP response was present in 35% of patients and was associated with increased 90 day all-cause mortality (unadjusted HR 9.16, 95% CI 1.98-42; P = 0.0046). Hazard ratio remained significant after adjusting for age, INTERMACS profile, serum creatinine, and total bilirubin. Findings were similar in the HM III subgroup.

CONCLUSIONS

Hypotensive SBP response on pre-LVAD CPX is associated with increased perioperative and 90 day mortality after LVAD implantation. Additional studies are needed to determine the mechanism of increased mortality observed.

Improvement of cardiopulmonary function after minimally invasive surgical repair of pectus excavatum (Nuss procedure) in children

Background:

Severe pectus excavatum in children may result in cardiorespiratory functional impairment; therefore, we evaluated cardiopulmonary response to exercise before and after the Nuss procedure.

Methods:

Twenty-four physically active pediatric patients aged 9–18 years with severe pectus excavatum (Haller index >3.25) were included in the study. Cardiopulmonary exercise testing using treadmill and modified Bruce protocol was performed before and after the Nuss procedure.

Results:

Maximal oxygen uptake and oxygen pulse improved by 40.6% (32 ± 13–45 ± 10 ml/kg/min; P = 0.0001) and 44.4% (9 ± 4–13 ± 5 ml/beat; P = 0.03), respectively, after surgical correction of pectus excavatum by Nuss procedure. Significant improvement in maximum voluntary ventilation and minute ventilation after Nuss procedure was also noted.

Conclusions:

We found that, after repair of pectus excavatum by Nuss procedure, the exercise capacity as measured by maximal oxygen consumption improved significantly primarily due to increase in oxygen pulse, an indirect measurement of stroke volume.