Relationship between Coronary Artery Calcium Score and Coronary Stenosis.

Background: The coronary artery calcium score (CACS) is commonly employed to quantify the degree of calcification in coronary atherosclerosis. Indeed, increased coronary stenosis severity is associated with a progressive increase in CACS. Objectives: This study sought to explore the association between CACS and coronary stenosis of ≥50% and ≥70%. Methods: We conducted a retrospective analysis of patient data collected between July 1, 2017, and March 3, 2022, at Jiangmen Central Hospital. A total of 208 patients, presenting with both symptomatic and asymptomatic manifestations and suspected coronary artery disease (CAD), were included. Statistical analyses included ROC curve assessments, subgroup analyses based on age, and comparisons of CACS values against the presence of coronary stenosis ≥50% and ≥70%. Results: Ultimately, 208 patients were included, with a median age of 65.0 years and a median CACS of 115.7 (interquartile range: 13.7-369.4). A CACS threshold of ≥1300 demonstrated a specificity of 100% for coronary stenosis of ≥50%. Notably, the percentage of patients with obstructive CAD showing CACS = 0 was significantly higher in those under 65 years (15.1%) compared to patients over 65 years (3.8%) (P=0.005). The inflection point, at which the risk probability for coronary stenosis of ≥50% shifted from being a protective factor to a risk factor, was observed when CACS fell within the range of 63.3 to 66.0. Conclusion: CACS demonstrates good performance for the detection of coronary artery stenosis.

Appraisal of guidelines for managing contrast medium in patients with metformin: consensuses, controversies, and gaps.

OBJECTIVES: The current guidelines contain substantial inconsistency regarding the use of metformin concomitantly with contrast media. The objective of this study is to appraise the guidelines and summarize the agreements and differences among recommendations. METHODS: Our search focused on English language guidelines published between 2018 and 2021. Guidelines for the management of contrast media in patients with continuous metformin were included. Guidelines were assessed using the Appraisal of Guidelines for Research and Evaluation II instrument. RESULTS: Six guidelines out of 1134 fulfilled the inclusion criteria with an AGREE II score of 79.2% (IQR 72.7 to 85.1%). There was good overall quality of the guidelines, with six considered "strongly recommended." CPGs scored poorly in "Clarity of Presentation" and "Applicability," with scores of 75.9% and 76.4%, respectively. The intraclass correlation coefficients were excellent in each domain. There are some guidelines (33.3%) that recommend discontinuation of metformin in patients with an eGFR of < 30 mL/min/1.73 m2, while some guidelines (16.7%) suggest the threshold of renal function should be eGFR < 40 mL/min/1.73 m2. CONCLUSIONS: Most guidelines recommend withdrawing metformin before using contrast agents in diabetic patients with severely impaired kidney function but disagree on the renal function thresholds. Furthermore, the gaps regarding discontinuing metformin with moderate renal impairment (30 mL/min/1.73 m2 < eGFR < 60 mL/min/1.73 m2) must be considered in future studies. KEY POINTS: • Guidelines involving metformin and contrast agents are reliable and optimal. • Most guidelines advocate discontinuing metformin before using contrast agents in diabetic patients with advanced renal failure, but there are controversial suggestions regarding kidney function thresholds. • The gaps regarding the time of discontinuation of the metformin with moderate renal impairment (30 mL/min/1.73 m2 < eGFR < 60 mL/min/1.73 m2) must be considered in the extensive RCT studies.