Article Impact Level: HIGH Data Quality: STRONG Summary of European Heart Journal, ehae827. https://doi.org/10.1093/eurheartj/ehae827 Dr. Ana Carolina do A. H. Souza et al.
Points
- The study examined the relationship between skeletal muscle (SM) quality, coronary microvascular dysfunction (CMD), and cardiovascular outcomes in 669 patients using cardiac stress PET and muscle/adipose tissue imaging.
- Lower coronary flow reserve (CFR) was independently linked to decreased SM and increased intermuscular adipose tissue (IMAT), both of which significantly contribute to coronary microvascular dysfunction (CMD).
- Higher IMAT increased the risk of major adverse cardiovascular events (MACEs) by 53% per 10 cm² increase. In contrast, higher SM and subcutaneous adipose tissue (SAT) were protective, reducing risk by 11% and 6% per 10 cm² increase.
- Each 1% rise in the fatty muscle fraction (IMAT/(SM + IMAT)) raised CMD odds by 2% and the risk of MACEs by 7%, highlighting the detrimental role of muscle fat infiltration.
- The findings identify a novel cardiometabolic phenotype, characterized by CMD and SM fat infiltration, as a marker for higher cardiovascular risk, independent of BMI and traditional factors.
Summary
This study investigated the relationship between skeletal muscle (SM) quality, coronary microvascular dysfunction (CMD), and cardiovascular outcomes. The research included 669 patients with normal perfusion and preserved left ventricular ejection fraction, followed over a median period of six years for major adverse cardiovascular events (MACEs), such as myocardial infarction, heart failure, and death. Data were obtained using cardiac stress positron emission tomography (PET), and coronary flow reserve (CFR) was calculated as the stress/rest myocardial blood flow ratio. Skeletal muscle, subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) areas were measured using PET-attenuation correction computed tomography at the 12th thoracic vertebra level.
The results revealed that BMI was strongly correlated with SAT and IMAT (r = 0.84 and r = 0.71, respectively, P < 0.001), but only decreased SM and increased IMAT were independently associated with lower CFR (adjusted P = 0.03 and P = 0.04, respectively). Lower CFR and higher IMAT were significantly associated with an increased risk of MACEs, with a hazard ratio of 1.78 (95% CI, 1.23–2.58) per unit decrease in CFR and 1.53 (95% CI, 1.30–1.80) per 10 cm² increase in IMAT (adjusted P = 0.002 and P < 0.0001, respectively). Conversely, higher SM and SAT were protective, with hazard ratios of 0.89 (95% CI, 0.81–0.97) per 10 cm² increase in SM and 0.94 (95% CI, 0.91–0.98) per 10 cm² increase in SAT (adjusted P = 0.01 and 0.003, respectively). Additionally, every 1% increase in fatty muscle fraction (IMAT/(SM + IMAT)) independently raised the odds of CMD by 2% (odds ratio 1.02, 95% CI, 1.01–1.04, adjusted P = 0.04) and increased the risk of MACE by 7% (hazard ratio 1.07, 95% CI, 1.04–1.09, adjusted P < 0.001).
This study highlights that increased intermuscular fat is independently associated with CMD and adverse cardiovascular outcomes beyond the impact of BMI and traditional risk factors. The findings suggest a novel cardiometabolic phenotype characterized by CMD and SM fat infiltration, which may identify patients at higher cardiovascular risk.
Link to the article: https://academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehae827/7958241
References Souza, A. C. D. A. H., Troschel, A. S., Marquardt, J. P., Hadžić, I., Foldyna, B., Moura, F. A., Hainer, J., Divakaran, S., Blankstein, R., Dorbala, S., Di Carli, M. F., Aerts, H. J. W. L., Lu, M. T., Fintelmann, F. J., & Taqueti, V. R. (2025). Skeletal muscle adiposity, coronary microvascular dysfunction, and adverse cardiovascular outcomes. European Heart Journal, ehae827. https://doi.org/10.1093/eurheartj/ehae827
