Background: Left atrial appendage (LAA) occlusion provides an alternative to oral anticoagulation (OAC) for thromboembolic risk reduction in patients with non-valvular atrial fibrillation (NVAF). Since regulatory approval in 2015, the WATCHMAN device has been the only LAA closure device available for clinical use in the United States. The PINNACLE FLX study evaluated the safety and effectiveness of the next-generation WATCHMAN FLX LAA closure device in patients with NVAF in whom OAC is indicated, but who have an appropriate rationale to seek a non-pharmaceutical alternative. Methods: This was a prospective, non-randomized, multi-center FDA study. The primary safety endpoint was the occurrence of one of the following events within 7 days post-procedure or by hospital discharge, whichever was later: death, ischemic stroke, systemic embolism, or device- or procedure-related events requiring cardiac surgery. The primary effectiveness endpoint was the incidence of effective LAA closure (peri-device flow ≤5mm), as assessed by the echocardiography core laboratory at 12-month follow-up. Results: A total of 400 patients were enrolled. The mean age was 73.8{plus minus}8.6 years and the mean CHA2DS2-VASc score was 4.2{plus minus}1.5. The incidence of the primary safety endpoint was 0.5% with a one-sided 95% upper confidence interval (CI) of 1.6%, meeting the performance goal (PG) of 4.2% (P<0.0001). The incidence of the primary effectiveness endpoint was 100%, with a onesided 95% lower CI of 99.1%, again meeting the PG of 97.0% (P<0.0001). Device-related thrombus was reported in 7 patients, no patients experienced pericardial effusion requiring open cardiac surgery, and there were no device embolizations. Conclusions: LAA closure with this next generation LAA closure device was associated with a low incidence of adverse events and a high incidence of anatomic closure. Clinical Trial Registration: URL https://clinicaltrials.gov Unique Identifier NCT02702271

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Collectively, these data suggest an age-associated increase in endothelial modulation of coronary resistance vessel constriction. This enhanced endothelial attenuation of coronary arteriolar constriction appears to result from increased basal release of nitric oxide. These alterations of coronary vascular reactivity may contribute to age-induced redistribution of coronary blood flow and diminished cardiac function.

Impairment of flow-induced vasodilation in coronary resistance arterioles may contribute to the decline in coronary vasodilatory reserve that occurs with advancing age. This study investigated the effects of age on flow-induced signaling and activation of nitric oxide (NO)-mediated vasodilation in coronary resistance arterioles. Coronary arterioles were isolated from young (approximately 6 mo) and old (approximately 24 mo) male Fischer-344 rats to assess vasodilation to flow, vascular endothelial growth factor (VEGF), and ACh. Flow- and VEGF-induced vasodilation of coronary arterioles was impaired with age (P

Objective-Exercise training has been shown to restore vasodilation to nitric oxide synthase (NOS) activation in arterioles distal to coronary artery occlusion. Because reactive oxygen species are generated during NOS uncoupling and the production of vasodilator H 2 O 2 is increased during exercise in patients with coronary disease, we proposed that H 2 O 2 may contribute to the restoration of vasodilation in porcine coronary occlusion model. Methods and Results-Left circumflex (LCX) coronary artery of miniature swine was progressively occluded for 8 weeks followed by exercise training (EX; 5 days/wk treadmill) or sedentary (SED) protocols for 12 weeks. Arterioles were isolated from distal LCX and nonoccluded left anterior descending (LAD) artery for in vitro study. Vasodilation to NOS activators adenosine and ionomycin was impaired in SED LCX, but not LAD, arterioles. This impairment was restored by L-arginine. NO production induced by adenosine was also reduced in SED LCX arterioles. EX had no effect on LAD arterioles but improved NO production and restored dilation of LCX arterioles. NOS blockade (L-NAME) inhibited vasodilation to NOS activators in LAD (SED & EX) arterioles but was ineffective in SED LCX arterioles. In EX LCX arterioles, vasodilation to NOS activators was slightly inhibited by L-NAME but abolished by catalase. H 2 O 2 production was markedly increased by adenosine in EX LCX arterioles. Conclusions-This study demonstrates that endothelium-dependent NO-mediated dilation is impaired in SED LCXarterioles and that EX training restores the impaired function. It appears that H 2 O 2 , in addition to NO, contributes significantly to EX-induced restoration of endothelium-dependent dilation of coronary arterioles distal to occlusion.