Metformin is the most widely prescribed drug to lower glucose and has a definitive effect on the cardiovascular system. The goal of this systematic review and meta-analysis is to assess the effects of metformin on mortality and cardiac function among patients with coronary artery disease (CAD). Relevant studies reported before October 2018 was retrieved from databases including PubMed, EMBASE, Cochrane Library and Web of Science. Hazard ratio (HR) was calculated to evaluate the all-cause mortality, cardiovascular mortality and incidence of cardiovascular events (CV events), to figure out the level of left ventricular ejection fraction (LVEF), creatine kinase MB (CK-MB), type B natriuretic peptide (BNP) and to compare the average level of low density lipoprotein (LDL). In this meta-analysis were included 40 studies comprising 1,066,408 patients. The cardiovascular mortality, all-cause mortality and incidence of CV events were lowered to adjusted HR (aHR) = 0.81, aHR = 0.67 and aHR = 0. 83 respectively after the patients with CAD were given metformin. Subgroup analysis showed that metformin reduced all-cause mortality in myocardial infarction (MI) (aHR = 0.79) and heart failure (HF) patients (aHR = 0.84), the incidence of CV events in HF (aHR = 0.83) and type II diabetes mellitus (T2DM) patients (aHR = 0.83), but had no significant effect on MI (aHR = 0.87) and non-T2DM patients (aHR = 0.92). Metformin is superior to sulphonylurea (aHR = 0.81) in effects on lowering the incidence of CV events and in effects on patients who don’t use medication. The CK-MB level in the metformin group was lower than that in the control group standard mean difference (SMD) = − 0.11). There was no significant evidence that metformin altered LVEF (MD = 2.91), BNP (MD = − 0.02) and LDL (MD = − 0.08). Metformin reduces cardiovascular mortality, all-cause mortality and CV events in CAD patients. For MI patients and CAD patients without T2DM, metformin has no significant effect of reducing the incidence of CV events. Metformin has a better effect of reducing the incidence of CV events than sulfonylureas.

The methods for calculating the optimal myocardial blood flow (MBF) relative parameters in stress dynamic myocardial CT perfusion (CTP) in the detection of hemodynamically significant coronary artery disease (CAD) are non-uniform and lack standards. A total of 86 patients who were prospectively recruited underwent APT stress dynamic myocardial CTP. The relative MBF perfusion parameters were calculated as av_Ratio, Q3av_Ratio and hi_Ratio according to the three types of reference MBF values, respectively: (1) average segmental MBF value, (2) the third quartile of the average segmental MBF value, and (3) highest segmental MBF value. All the data were derived from both the endocardial and transmural layers of the myocardium. Invasive coronary angiography and fractional flow reserve (ICA/FFR) were used as the reference standards for myocardial ischemia evaluation. A total of 151 vessels of 60 patients (43 men and 17 women; 61.38 ± 8.01 years) were enrolled in the analysis. The performance of the endocardial layer was superior to that of the transmural layer (all P < 0.05). The hi_Ratio of the endocardial myocardium (AUC = 0.906, 95% CI: 0.857-0.954), for which the highest segmental value was selected as the reference MBF, was superior to both av_Ratio and Q3av_Ratio for ischemia detection (AUC, 0.906 vs.0.879, P < 0.05; 0.906 vs.0.891, P = 0.18), and the sensitivity, specificity, PPV, NPV and diagnostic accuracy were 74.1%, 93.6%, 87.8%, 85.3% and 86.1%, respectively. The cutoff value of hi_Ratio was 0.675. The relative MBF parameter of the endocardial myocardium using the highest segmental MBF value as a reference provided optimal diagnostic accuracy for the detection of hemodynamically significant CAD.

The precise relationship between increased thrombolysis in myocardial infarction (TIMI) frame counts and the topographical extent of isolated coronary artery ectasia (CAE) has not been fully explained. New parameters of linear dimension (LD) and the estimated ectatic area (EEA) together with the diameter and ectasia ratio may be associated with the corrected TIMI frame count (CTFC) in isolated CAE patients. The topographical parameters of ectatic coronary arteries and/or segments of 77 isolated CAE patients were consecutively studied. The CTFC for each coronary artery was determined by angiographic frame count. Right coronary artery (RCA) was the most frequently affected. The RCA and left circumflex (LCX) had significantly longer LD (p < 0.001 for both), and greater EEA (p < 0.001 for both) than those of left anterior descending artery (LAD). Similarly, the RCA and LCX have higher CTFCs (p = 0.001 and p = 0.008, respectively) than LAD. All topographic parameters and CTFCs were positively correlated with Markis classification. Linear regression analyses revealed that CTFCs were strongly correlated with diameter, LD, ectasia ratio and EEA, while EEA was the best predictor for the CTFC. Among multiple linear and nonlinear regression models, the cubic model between the CTFC and EEA exhibits the best Goodness-of-Fit. The severity of the topographical extent of CAE was significantly correlated with increased CTFCs. Both the linear dimension and ectatic diameter (combined as EEA) were important for evaluating decreased coronary flow in isolated CAE patients.

Background: The FAVOR III (Comparison of Quantitative Flow Ratio Guided and Angiography Guided Percutaneous Intervention in Patients With Coronary Artery Disease) China trial reported improved clinical outcomes with percutaneous coronary intervention guided by quantitative flow ratio (QFR) compared with angiography. Whether these benefits also apply for patients presenting with “uncertainty‐zone” lesions of intermediate physiological significance is uncertain. This study aims to examine the impact of QFR guidance versus angiography guidance on the management and outcomes of percutaneous coronary intervention in uncertainty‐zone lesions. Methods and Results: In this prespecified subgroup analysis, offline QFR assessment categorized 873 patients (22.9%) into the uncertainty‐zone subgroup, defined as having an offline QFR of 0.75 to 0.85 in all coronary arteries with a lesion causing ≥50% diameter stenosis. At 2 years, the rate of major adverse cardiac events, a composite of all‐cause death, myocardial infarction, or ischemia‐driven revascularization, occurred in 31 patients (7.0%) in the QFR‐guided group and 35 patients (8.3%) in the angiography‐guided group (hazard ratio [HR], 0.85 [95% CI, 0.52–1.37]). In landmark analysis, the relative treatment effect of QFR guidance versus angiography guidance on major adverse cardiac events differed before 1 year (4.7% versus 3.8%; HR, 1.25 [95% CI, 0.65–2.40]) and after 1 year (2.3% versus 5.5%; HR, 0.41 [95% CI, 0.20–0.87]) ( P _interaction =0.03), driven by fewer nonprocedural myocardial infarctions and ischemia‐driven revascularizations in the QFR‐guided group after 1‐year follow‐up. Conclusions: In the modest‐sized subgroup of patients with physiologically intermediate lesions randomized in the FAVOR III China trial, 2‐year clinical outcomes were not significantly improved with a QFR‐guided revascularization strategy compared with angiography guidance. Registration: URL: https://www.clinicaltrials.gov ; Identifier: NCT 03656848.