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INTRODUCTION: Coronary microvascular dysfunction (CMD) is common in patients with and without obstructive epicardial coronary artery disease (CAD). Risk factors for the development of CMD have not been fully elucidated, and data regarding sex-associated differences in traditional cardiovascular risk factors for obstructive CAD in patients with CMD are lacking. METHODS: In this single-center, prospective registry, we enrolled patients with nonobstructive CAD undergoing clinically indicated invasive assessment of coronary microvascular function between November 2019 and March 2023. Associations between coronary microvascular dysfunction, traditional cardiovascular risk factors, and sex were assessed using univariate and multivariate regression models. RESULTS: Overall, 245 patients with nonobstructive CAD were included in the analysis (62.9% female; median age 68 (interquartile range: 59, 75). Microvascular dysfunction was diagnosed in 141 patients (57.5%). The prevalence of microvascular dysfunction was similar in women and men (59.0% vs. 57.0%; p = 0.77). No association was found between traditional risk factors for coronary atherosclerosis and CMD regardless of whether CMD was structural or functional. In women, but not in men, older age and the presence of previous ischemic heart disease were associated with lower coronary flow reserve (ß = -0.29; p < 0.01 and ß = -0.15; p = 0.05, respectively) and lower resistive reserve ratio (ß = -0.28; p < 0.01 and ß = -0.17; p = 0.04, respectively). CONCLUSION: For the entire population, no association was found between coronary microvascular dysfunction and traditional risk factors for coronary atherosclerosis. In women only, older age and previous ischemic heart disease were associated with coronary microvascular dysfunction. Larger studies are needed to elucidate risk factors for CMD.
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BACKGROUND: The pathophysiology of Takotsubo syndrome (TTS) remains incompletely understood. While coronary microvascular dysfunction (CMD) is a potential pathophysiologic mechanism, evidence is limited. OBJECTIVES: We sought to evaluate CMD in patients with TTS. METHODS: Consecutive patients diagnosed with TTS were included and underwent coronary angiography with invasive microvascular function evaluation, including fractional flow reserve, Coronary Flow Reserve (CFR), Index of Microcirculatory Resistance (IMR), and Resistive Reserve Ratio (RRR). Patients had an echocardiography evaluation during their index admission and at approximately 6 weeks. RESULTS: Thirty patients were included (mean age 74 ±9, 90 % female). Twenty-five patients (83 %) had at least one abnormal coronary microvascular function parameter. Abnormal parameters included CFR<2.5 in 20 patients (67 %), IMR>25 in 18 patients (60 %), and RRR<3.5 in 25 (83 %). Longer time from symptoms to angiography correlated with a higher CFR (r = 0.51, P<0.01), and had an area under the receiver operating characteristic curve of 0.793 (95 % CI 0.60-0.98) for pathologic CFR. Patients with emotional trigger had a lower rate of pathologic IMR compared with non-emotional trigger (36 % vs 81 %, p = 0.01). Follow up echocardiography performed at a median of 1.5 months (IQR 1.15-6) showed an improvement in left ventricular ejection fraction for all patients (from mean of 40 % to 57 %). CONCLUSION: CMD was present in most patients with TTS. The role of microvascular function in TTS may vary according to the clinical presentation and RRR may be more sensitive for the diagnosis of CMD in TTS.
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BACKGROUND: The Food and Drug Administration (FDA)'s Adverse Event Reporting System (FAERS) is a post-marketing surveillance system which relies on spontaneous reports of adverse drug reactions (ADRs). Our objective was to evaluate how black box warning (BBW) updates impact ADR reporting rates. RESEARCH DESIGN AND METHODS: We searched MEDWATCH for all BBW updates issued between January 2014 and December 2016 and categorized them as new, major, and minor. Rates of relevant ADR reports from the FAERS database in the 4 years preceding and following a BBW update were assessed among the different BBW categories. RESULTS: Forty BBW updates were included (16 major, 3 new, and 21 minor). A meaningful increase in the proportion of relevant ADRs of all ADRs reported following BBW updates was documented for 53% of new or major updates and 24% of minor updates (p = 0.06). The median percentage of reported relevant ADRs increased by 5% following new and major BBW updates and decreased by 30% following minor BBW updates (p = 0.3). CONCLUSIONS: Reporting of adverse events to the FAERS database is affected by the severity and timing of related BBW updates, highlighting the drawbacks of spontaneous reporting systems. Regulators should promote proactive pharmacovigilance strategies to cope with these limitations.