Matthew Best

Nitric oxide is not obligatory for radial artery flow-mediated dilation following release of 5 or 10 min distal occlusion.

This study investigated the nitric oxide (NO) dependence of radial artery (RA) flow-mediated dilation (FMD) in response to three different reactive hyperemia (RH) shear stimulus profiles. Ten healthy males underwent the following three RH trials: 1) 5 min occlusion (5 trial), 2) 10 min occlusion (10 trial), and 3) 10 min occlusion with cuff reinflation at 30 s (10-30 trial). Trials were performed during saline infusion and repeated during N(G)-monomethyl-L-arginine (L-NMMA) infusion in the brachial artery. RA blood flow velocity was measured with Doppler ultrasound, and B-mode RA images were analyzed using automated edge detection software. Shear rate estimation of shear stress was calculated as the blood flow velocity/vessel diameter. L-NMMA decreased baseline vascular conductance by 35%. L-NMMA infusion did not affect the peak shear rate stimulus (P = 0.681) or the area under the curve (AUC) of shear rate to peak FMD (P = 0.088). The AUC was significantly larger in the 10 trial vs. the 10-30 or 5 trial (P < 0.001). Although percent FMD (%change in diameter) in the 10 trial was larger than that in the 5 trial (P = 0.035), there was no significant difference in %FMD between the saline and L-NMMA conditions in any trial: 5 trial, 5.62 +/- 1.48 vs. 5.63 +/- 1.27%; 10 trial, 9.07 +/- 1.16 vs. 11.22 +/- 2.21%; 10-30 trial, 6.52 +/- 1.43 vs. 7.98 +/- 1.51% for saline and L-NMMA, respectively (P = 0.158). We conclude the following: 1) RH following 10 min of occlusion results in an enhanced stimulus and %FMD compared with 5 min of occlusion. 2) When the occlusion cuff is reinflated 30 s postrelease of a 10 min occlusion, it does not result in an enhanced %FMD compared with that which results from RH following 5 min of occlusion. 3) The lack of effect of L-NMMA on FMD suggests that NO may not be obligatory for radial artery FMD in response to either 5 or 10 min of occlusion in healthy volunteers.

Repeated infusions of levosimendan: well tolerated and improves functional capacity in decompensated heart failure - a single-centre experience.

BACKGROUND Levosimendan is a novel agent used in the treatment of patients with decompensated heart failure to enhance cardiac contractility. Recent clinical studies have demonstrated that single doses of levosimendan have positive symptomatic and haemodynamic benefits, few have explored the efficacy and safety of intermittent repeated doses of levosimendan. AIMS In this prospective study we document our single-centre experience of repeated administration of levosimendan to patients with decompensated heart failure. METHODS Prospective data were collected and analysed with respect to New York Heart Association (NYHA) class, mean arterial pressure (MAP), brain natriuretic peptide levels (BNP) and adverse events. RESULTS Forty-four consecutive patients with decompensated heart failure received repeated doses of levosimendan. The mean dosing interval was 66.2 (12) days. All patients had documented evidence of impaired left ventricular function, with a mean ejection fraction (EF) of 23.7% (2.2). Fifty-eight percent were NYHA class IV, mean age 50 (2.4), 82% were male. A significant drop in BNP levels and improvement in NYHA class was seen post-infusion. In general, levosimendan was well tolerated with 130 (83.5%) infusions completed without an adverse event. Twenty-five percent of patients were bridged to cardiac transplant or left ventricular assist device (LVAD) insertion. Four patients received 12 infusions, in total in the community. CONCLUSION The majority of repeated levosimendan infusions were well tolerated, reduced BNP and improved NYHA functional class. In selected patients it can be administered in the community. Further investigation is required to assess the efficacy and safety of this approach.

Improved Quality of Life Two-years Post Transcatheter Aortic Valve Replacement for a Regurgitant Aortic Homograft

The limited durability of prosthetic cardiac valves together with an aging population will present ongoing management challenges. This paper describes the case of an 82 year-old male with symptomatic severe regurgitation in an aortic homograft which remains successfully treated with Transcatheter Aortic Valve Replacement (TAVR) at two-year follow-up.