Low skeletal muscle density combined with muscle dysfunction predicts adverse events after adult cardiovascular surgery
Masashi Yamashita, Nutrition, Metabolism and Cardiovascular Diseases Articles in Press E-mail Alert - February 24, 2021
Highlights
• Skeletal muscle density (SMD) reflects the intramuscular fat and muscle fiber size.
• Added low SMD enhanced the ability to predict adverse events in muscle dysfunction.
• Patients with muscle dysfunction and low SMD had the highest risk of death.
• The organic assessment of skeletal muscle may help identify muscle wasting.
Background and Aims
Although muscle dysfunctions are widely known as a poor prognostic factor in patients with cardiovascular disease, no study has examined whether the addition of low skeletal muscle density (SMD) assessed by computed tomography (CT) to muscle dysfunctions is useful. This study examined whether SMDs can strengthen the predictive ability of muscle dysfunctions for adverse events in patients who underwent cardiovascular surgery.
Methods and Results
We retrospectively reviewed 853 patients aged ≥ 40 years who had preoperative CT for risk management purposes and who measured muscle dysfunctions (weakness: low grip strength and slowness: slow gait speed). Low SMD based on transverse abdominal CT images was defined as a mean Hounsfield unit of the psoas muscle < 45. All definitions of muscle dysfunction (weakness only, slowness only, weakness or slowness, weakness and slowness), the addition of SMDs was shown to significantly improve the continuous net reclassification improvement and integrated discrimination improvement for adverse events in all analyses ( p <0.05). Low SMDs combined with each definition of muscle dysfunction had the highest risk of all-cause death (hazard ratio: lowest 3.666 to highest 6.002), and patients with neither low SMDs nor muscle dysfunction had the lowest risk of all-cause and cardiovascular-related events.
Conclusion
The addition of SMDs consistently increased the predictive ability of muscle dysfunctions for adverse events. Our results suggest that when CT is performed for any clinical investigation, the addition of the organic assessment of skeletal muscle can strengthen the diagnostic accuracy of muscle wasting.