Clinical Implication of Coronary Artery Calcium Score in Survivors of Out-of-Hospital Cardiac Arrest

Variation in practice for out-of-hospital cardiac arrest treated with percutaneous coronary intervention in England and Wales

OBJECTIVES

We assessed the association between total center volume, operator volume, and out-of-hospital cardiac arrest (OHCA) percutaneous coronary intervention (PCI) volume.

BACKGROUND

Variations between OHCA PCI volume, hospital total PCI, and primary PCI volume are not well studied and are unlikely to be clinically justifiable.

METHODS

Patients undergoing PCI for the acute coronary syndrome (ACS) between January 1, 2014, and March 31, 2019, in England and Wales were grouped as OHCA PCI and non-OHCA PCI. Spearman's correlation was used to determine the degree of correlation between each hospital PCI volume and OHCA PCI volume.

RESULTS

Out of 250,088 PCI procedures undertaken for ACS, 12,016 (4.8%) were performed for OHCA, and 238,072 (95.2%) were non-OHCA PCI procedures. The OHCA PCI group were younger [mean age (SD) 63.2 (12.3) and 65.6 (12.5, p < 0.001)], less likely to be female (20.2% vs. 26.9%, p < 0.001) or Black, Asian, and Minority Ethnicity (11.5% vs. 14.8%, p < 0.001) compared to the non-OHCA PCI group. Although there was a degree of correlation between total PCI and OHCA PCI, there was wide variation for both ACS cohort (Spearman correlation R²  = 0.50) and total PCI volume (Spearman correlation R²  = 0.60). Furthermore, the correlation between primary PCI volume and OHCA PCI within centers was weak (R²  = 0.10). Similarly, wide variations between operator PCI volume and OHCA PCI volume were observed.

CONCLUSION

These national data demonstrate wide variation in the practice of OHCA PCI both between centers and individuals. These variations are not expected according to clinical factors and require further investigation.

Prognostic Value of Psoas Muscle Mass Index in Patients With Non‒ST-Segment‒Elevation Myocardial Infarction: A Prospective Observational Study

Background Muscle wasting is an important predictor of long-term outcome in patients with cardiovascular disease, but the prognostic value of muscle wasting in patients with non‒ST-segment‒elevation myocardial infarction is not established. The aim of this study is to investigate the prognostic value of muscle wasting, defined by psoas muscle mass index (PMI), in patients with non‒ST-segment‒elevation myocardial infarction. Methods and Results A total of 132 consecutive patients with non‒ST-segment‒elevation myocardial infarction were prospectively enrolled between 2015 and 2018. Primary end point was incidence of cardiovascular events including cardiovascular deaths, non-fatal myocardial infarction, or non-fatal stroke. Cross-sectional area of the psoas muscle at the L3 vertebral level was obtained by computed tomography and PMI was calculated. The median follow-up period was 2.4 years (interquartile range, 1.1-4.0 years). There were 45 cardiovascular events (34%) during the study periods. The optimal cutoff value of PMI to predict cardiovascular events was 772 mm2/m2, as assessed by receiver operating curve analysis. Patients with reduced PMI (PMI<772 mm2/m2) had significantly higher cardiovascular events than those with preserved PMI (PMI≥772 mm2/m2) (48% versus 21%; log-rank test P<0.001). Multivariate Cox proportional hazards model revealed that reduced PMI was a statistically significant predictor of cardiovascular events (hazard ratio, 3.30; 95% CI, 1.70-6.40; P<0.001). Conclusions Muscle wasting defined as PMI is a simple and useful objective marker to predict future cardiovascular outcome in patients with non‒ST-segment‒elevation myocardial infarction. Registration Information URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000013445.

Coronary artery calcification as a novel predictive marker of unstable coronary lesion in survivors of out-of-hospital cardiac arrest without ST-segment elevation

AIM

Acute myocardial infarction (AMI) is the leading cause of out-of-hospital cardiac arrest (OHCA). A highly predictive marker is needed to identify AMI in survivors of OHCA without ST-segment elevation because the appropriate indication for emergency coronary artery angiography in patients without ST-segment segment elevation has not been determined. Accordingly, the aim of this study was to elucidate the clinical significance of coronary artery calcification in identifying survivors of OHCA without ST-segment elevation who could benefit from emergency coronary artery angiography.

METHODS

Survivors of OHCA without ST-segment elevation with no obvious extra-cardiac cause who underwent emergency computed tomography and coronary artery angiography were enrolled. Unstable coronary lesion was diagnosed using coronary artery angiography, and presence of coronary artery calcification and coronary artery calcium score were evaluated by non-contrast, non-electrocardiography gated computed tomography.

RESULTS

Thirty of 100 consecutive survivors of OHCA were diagnosed to have unstable coronary lesion. Sensitivity and specificity of coronary artery calcification in identifying unstable coronary lesion were 87% and 60%, respectively. Multivariate logistic regression analysis revealed that coronary artery calcification was an independent predictor of unstable coronary lesion (odds ratio: 7.28, 95% confidence interval: 2.00-26.56, p < 0.001).

CONCLUSION

Evaluation of coronary artery calcification by computed tomography is useful in identifying patients with unstable coronary lesion who could benefit from emergency coronary artery angiography among survivors of OHCA without ST-segment elevation on post-resuscitation electrocardiography.