Postinfarction Myocardial Calcifications on Cardiac Computed Tomography: Implications for Mapping and Ablation in Patients With Nontolerated Ventricular Tachycardias.

BACKGROUND: Postinfarction ventricular tachycardia (VT) generally involves myocardial fibers surrounded by scar. Calcification of scar tissue has been described, but the relationship between calcifications within endocardial scar and VTs is unclear. The purpose of this study was to assess the prevalence of myocardial calcifications as detected by cardiac computed tomography (CT) and the benefit for mapping and ablation focusing on nontolerated VTs. METHODS: Fifty-six consecutive postinfarction patients had a cardiac CT performed before a VT ablation procedure. Another 56 consecutive patients with prior infarction without VT who had cardiac CTs served as a control group. RESULTS: Myocardial calcifications were identified in 39 of 56 patients (70%) in the postinfarction group with VT, compared with 6 of 56 patients (11%) in the control group without VT. Calcifications were associated with VT when compared with a control group. A calcification volume of 0.538 cm3 distinguished patients with calcification-associated VT from patients without calcification-associated VTs (area under the curve, 0.87; sensitivity, 0.87; specificity, 0.88). Myocardial calcifications corresponded to areas of electrical nonexcitability and formed a border for reentry circuits for 49 VTs (33% of all VTs for which target sites were identified) in 24 of 39 patients (62%) with myocardial calcifications. A nonconfluent calcification pattern was associated with VT target sites independent of calcification volume ( P=0.01). CONCLUSIONS: Myocardial calcifications detected by cardiac CT in patients with prior infarction are associated with VT. The calcifications correspond to areas of unexcitability and represent a fixed boundary of reentry circuits that can be visualized by CT. Calcifications correspond to effective ablation sites in >1/3 of patients with postinfarction VT.

Exploring the Healthcare Value of Percutaneous Coronary Intervention: Appropriateness, Outcomes, and Costs in Michigan Hospitals.

BACKGROUND: Assessments of healthcare value have largely focused on measuring outcomes of care at a given level of cost with less attention paid to appropriateness. However, understanding how appropriateness relates to outcomes and costs is essential to determining healthcare value. METHODS AND RESULTS: In a retrospective cohort study design, administrative data from fee-for-service Medicare patients undergoing percutaneous coronary intervention (PCI) in Michigan hospitals between June 30, 2010, and December 31, 2014, were linked with clinical data from a statewide PCI registry to calculate hospital-level measures of (1) appropriate use criteria scores, (2) 90-day risk-standardized readmission and mortality rates, and (3) 90-day risk-standardized episode costs. We then used Spearman correlation coefficients to assess the relationship between these measures. A total of 29 839 PCIs were performed at 33 PCI hospitals during the study period. A total of 13.3% were for ST-segment-elevation myocardial infarction, 25.0% for non-ST-segment-elevation myocardial infarction, 47.1% for unstable angina, 9.8% for stable angina, and 4.7% for other. The overall hospital-level mean appropriate use criteria score was 8.4±0.2. Ninety-day risk-standardized readmission occurred in 23.7%±3.7% of cases, 90-day risk-standardized mortality in 4.3%±0.6%, and mean risk-standardized episode costs were $26 159±$1074. Hospital-level appropriate use criteria scores did not correlate with 90-day readmission, mortality, or episode costs. CONCLUSIONS: Among Medicare patients undergoing PCI in Michigan, we found hospital-level appropriate use criteria scores did not correlate with 90-day readmission, mortality, or episode costs. This finding suggests that a comprehensive understanding of healthcare value requires multidimensional consideration of appropriateness, outcomes, and costs.