Al Rifai Mahmoud, Alwan Maria, Ahmed Ahmed Ibrahim, Alnabelsi Talal, Aljizeeri Ahmed, Al-Mallah Mouaz H
Houston Methodist DeBakey Heart and Vascular Center, TX (M.A.R., M.A., A.I.A., T.A., M.H.A.-M.).
Yale University School of Medicine, New Haven, CT (A.I.A.).
Circ Cardiovasc Imaging. 2025 Sep;18(9):e018361. doi: 10.1161/CIRCIMAGING.125.018361. Epub 2025 Aug 7.
Coronary artery calcium (CAC) is a strong predictor of cardiovascular outcomes, with patients having high CAC experiencing event rates similar to those in secondary prevention populations. Emerging evidence suggests that patients with extremely high CAC (≥1000) represent a distinct high-risk group. Therefore, this study aims to evaluate the prognostic value of myocardial flow reserve (MFR) in patients with very high CAC.
Consecutive patients who had a clinically indicated positron emission tomography were enrolled and followed prospectively for incident outcomes (all-cause death and myocardial infarction). Multivariable-adjusted Cox proportional hazards models were used to study the association between MFR and incident events (composite of all-cause death and myocardial infarction) among those with CAC ≥400.
The study population consisted of 3091 patients; mean (SD) age 69.6 (10.1) years, 36.8% female, 64.5% White, 46.0% with a CAC score of 400 to 999, and 54.0% with a CAC score of ≥1000. The median (interquartile range) MFR was 1.9 (1.45-2.35). Over a median (interquartile range) follow-up time of 1.36 (0.45-2.50) years, there were 278 incident events (81 myocardial infarctions and 217 deaths). In adjusted analyses, an MFR ≥2 was inversely associated with a lower risk of incident events; hazard ratio, 0.65 (95% CI, 0.38-1.12) for a CAC score of 400 to 999 and hazard ratio, 0.44 (95% CI, 0.28-0.69) for a CAC score of ≥ 1000. There was no significant interaction between MFR and CAC score; =0.53.
Among patients with CAC ≥400, positron emission tomography-derived MFR ≥2 is inversely associated with a lower risk of all-cause death and myocardial infarction.
冠状动脉钙化（CAC）是心血管疾病预后的有力预测指标，CAC水平高的患者发生心血管事件的概率与二级预防人群相似。新出现的证据表明，CAC极高（≥1000）的患者代表一个独特的高危群体。因此，本研究旨在评估心肌血流储备（MFR）在CAC极高的患者中的预后价值。
纳入连续进行临床正电子发射断层扫描的患者，并对其进行前瞻性随访以观察不良事件（全因死亡和心肌梗死）。采用多变量调整的Cox比例风险模型研究CAC≥400的患者中MFR与不良事件（全因死亡和心肌梗死的复合事件）之间的关联。
研究人群包括3091例患者；平均（标准差）年龄69.6（10.1）岁，女性占36.8%，白人占64.5%，46.0%的患者CAC评分为400至999，54.0%的患者CAC评分≥1000。MFR的中位数（四分位间距）为1.9（1.45 - 2.35）。在中位（四分位间距）随访时间1.36（0.45 - 2.50）年期间，共发生278起不良事件（81例心肌梗死和217例死亡）。在调整分析中，MFR≥2与不良事件风险降低呈负相关；CAC评分为400至999时，风险比为0.65（95%可信区间，0.38 - 1.12），CAC评分≥1000时，风险比为0.44（95%可信区间，0.28 - 0.69）。MFR与CAC评分之间无显著交互作用；P = 0.53。
在CAC≥400的患者中，正电子发射断层扫描得出的MFR≥2与全因死亡和心肌梗死风险降低呈负相关。
