Background Heart failure (HF) is associated with the derangement of muscle structure and metabolism, contributing to exercise intolerance, frailty, and mortality. Reduced handgrip strength is associated with increased patient frailty and higher morbidity and mortality. We evaluated handgrip strength as a marker of muscle function and frailty for prediction of clinical outcomes after ventricular assist device (VAD) implantation in patients with advanced HF. Methods and Results Handgrip strength was measured in 72 patients with advanced HF before VAD implantation (2.3 ± 4.9 days pre-VAD). We analyzed dynamics in handgrip strength, laboratory values, postoperative complications, and mortality. Handgrip strength correlated with serum albumin levels (r = 0.334, P = .004). Compared with baseline, handgrip strength increased post-VAD implantation by 18.2 ± 5.6% at 3 months (n = 29) and 45.5 ± 23.9% at 6 months (n = 27). Patients with a handgrip strength <25% of body weight had an increased risk of mortality, increased postoperative complications, and lower survival after VAD implantation. Conclusion Patients with advanced HF show impaired handgrip strength indicating a global myopathy. Handgrip strength <25% of body weight is associated with higher postoperative complication rates and increased mortality after VAD implantation. Thus, the addition of measures of skeletal muscle function underlying the frailty phenotype to traditional risk markers might have incremental prognostic value in patients undergoing evaluation for VAD placement.

Objective To determine whether endothelin (ET)-1 vasoconstrictor tone is greater in overweight and obese adults with the metabolic syndrome (MetS). Materials/Methods Forty overweight/obese middle-aged and older adults (age: 43-71 years; BMI: 25.1-36.9 kg/m2) were studied: 20 without MetS (13 M/7 F) and 20 with MetS (13 M/7 F). MetS was established according to NCEP ATP III guidelines. Forearm blood flow (FBF; plethysmography) responses to intra-arterial infusion of selective ETA receptor blockade (BQ-123; 100 nmol/min; for 60 min) and non-selective ETA/B receptor blockade (BQ-123 + BQ-788 [50 nmol/min for 60 min]) were determined. Results In response to the selective ETA antagonism, there was a significant increase in forearm blood flow from baseline in both groups. However, the increase in forearm blood flow was significantly higher (P=0.03; ~45%) in the overweight/obese group with MetS than the group without MetS. In contrast, there were no significant group differences in FBF responses to non-selective ETA/B receptor blockade. Peak vasodilator responses to nonselective ETA/B blockade were ~50% higher than baseline blood flow in the overweight/obese groups without and with MetS. Conclusion MetS is associated with higher ET-1 vasoconstrictor tone in overweight/obese adults. The enhanced ET-1 vasoconstrictor activity with MetS is mediated by the ETA receptor subtype.

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The effects of continuous flow left ventricular assist device (CF-LVAD) support on microvascular endothelial function in New York Heart Association (NYHA) class IV heart failure (HF) patients are currently unknown. Microvascular endothelial function was assessed by beat-to-beat plethysmographic measurement of finger arterial pulse wave signal changes for 5 min following reactive hyperemia. A group of seven NYHA class IV HF patients was evaluated before CF-LVAD placement (HF), and a second group of six NYHA class IV HF patients was evaluated 1-4 months following CF-LVAD placement (CF-LVAD). Additionally, a third group of seven age-matched healthy subjects served as controls (control). There was no significant (P > 0.05) difference among the three groups in age, weight, or height. Systolic blood pressure (BP) was significantly higher in the control group (120 ± 2 mmHg) as compared to that in the HF (97 ± 8 mmHg, P = 0.005) and CF-LVAD (106 ± 4 mmHg, P = 0.003) groups. Diastolic BP was significantly lower in the HF group (57 ± 5 mmHg) as compared to that in the control (71 ± 2 mmHg, P = 0.012) and CF-LVAD (80 ± 7 mmHg, P = 0.008) groups. The reactive hyperemic index (RHI), a measure of endothelial function, was significantly higher in the control group (2.373 ± 0.274) than in both the HF (1.543 ± 0.173, P = 0.013) and CF-LVAD (1.355 ± 0.163, P = 0.004) groups; however, there was no significant (P = 0.223) difference in RHI between the HF and CF-LVAD groups. The results of the present study demonstrate that while 1-4 months of CF-LVAD support do not negatively affect microvascular endothelial function, 1-4 months of CF-LVAD support do not significantly improve vascular function in resistance vessels.