Efficacy of high-dose atorvastatin or rosuvastatin loading in patients with acute coronary syndrome undergoing percutaneous coronary intervention: a meta-analysis of randomized controlled trials with GRADE qualification of available evidence.

PURPOSE: We aimed to summarize current evidence regarding the impact of a high-dose statin loading before percutaneous coronary intervention (PCI) on short-term outcomes in patients presenting with the acute coronary syndrome (ACS). METHODS: This meta-analysis was based on a search of the MEDLINE, Cochrane Central Register of Controlled Trials, Ovid Journals, and SCOPUS for randomized controlled trials that compared high-dose atorvastatin or rosuvastatin with no or low-dose statin administered before planned PCI in statin-naive patients with ACS. The primary endpoints were major adverse cardiovascular and cerebrovascular events (MACCE), myocardial infarction (MI), and all-cause mortality at 30 days. Prespecified subanalyses were performed with respect to statin and ACS type. RESULTS: A total of eleven trials enrolling 6291 patients were included, of which 75.4% received PCI. High-dose statin loading was associated with an overall 43% relative risk (RR) reduction in MACCE at 30 days (RR 0.57, 95% CI 0.41-0.77) in whole ACS population. This effect was primarily driven by the 39% reduction in the occurrence of MI (RR 0.61, 95% CI 0.46-0.80). No significant effect on all-cause mortality reduction was observed (RR 0.92, 95% CI 0.67-1.26). In the setting of ST-elevation myocardial infarction (STEMI), atorvastatin loading was associated with a 33% reduction in MACCE (RR 0.67, 95% CI 0.48-0.94), while in non-ST-elevation myocardial infarction ACS (NSTE-ACS), rosuvastatin loading was associated with 52% reduction in MACCE at 30 days (RR 0.48, 95% CI 0.34-0.66). The level of evidence as qualified with GRADE was low to high, depending on the outcome. CONCLUSION: A high-dose loading of statins before PCI in patients with ACS reduces MACCE and reduces the risk of MI with no impact on mortality at 30 days. Atorvastatin reduces MACCE in STEMI while rosuvastatin reduces MACCE in NSTE-ACS at 30 days.

Inorganic nitrate and nitrite supplementation fails to improve skeletal muscle mitochondrial efficiency in mice and humans.

BACKGROUND: Inorganic nitrate, abundant in leafy green vegetables and beetroot, is thought to have protective health benefits. Adherence to a Mediterranean diet reduces the incidence and severity of coronary artery disease, whereas supplementation with nitrate can improve submaximal exercise performance. Once ingested, oral commensal bacteria may reduce nitrate to nitrite, which may subsequently be reduced to nitric oxide during conditions of hypoxia and in the presence of "nitrite reductases" such as heme- and molybdenum-containing enzymes. OBJECTIVE: We aimed to explore the putative effects of inorganic nitrate and nitrite on mitochondrial function in skeletal muscle. METHODS: Mice were subjected to a nitrate/nitrite-depleted diet for 2 wk, then supplemented with sodium nitrate, sodium nitrite, or sodium chloride (1 g/L) in drinking water ad libitum for 7 d before killing. Skeletal muscle mitochondrial function and expression of uncoupling protein (UCP) 3, ADP/ATP carrier protein (AAC) 1 and AAC2, and pyruvate dehydrogenase (PDH) were assessed by respirometry and Western blotting. Studies were also undertaken in human skeletal muscle biopsies from a cohort of coronary artery bypass graft patients treated with either sodium nitrite (30-min infusion of 10 µmol/min) or vehicle [0.9% (wt:vol) saline] 24 h before surgery. RESULTS: Neither sodium nitrate nor sodium nitrite supplementation altered mitochondrial coupling efficiency in murine skeletal muscle, and expression of UCP3, AAC1, or AAC2, and PDH phosphorylation status did not differ between the nitrite and saline groups. Similar results were observed in human samples. CONCLUSIONS: Sodium nitrite failed to improve mitochondrial metabolic efficiency, rendering this mechanism implausible for the purported exercise benefits of dietary nitrate supplementation. This trial was registered at clinicaltrials.gov as NCT04001283.