Recent developments in computed tomography (CT) technology have fulfilled the prerequisites for the clinical application of myocardial CT perfusion (CTP) imaging. The evaluation of myocardial perfusion by CT can be achieved by static or dynamic scan acquisitions. Although both approaches have proved clinically feasible, substantial barriers need to be overcome before its routine clinical application. The current review provides an outline of the current status of CTP imaging and also focuses on disparities between static and dynamic CTPs for the evaluation of myocardial blood flow.

Objective To examine sex-specific associations, if any, between per-vessel CAD extent and the risk of major adverse cardiovascular events (MACE) over a five-year study duration. Background The presence and extent of coronary artery disease (CAD) diagnosed by coronary computed tomography angiography (CCTA) is associated with increased short-term mortality and MACE. Nevertheless, some uncertainty remains regarding the influence of gender on these findings. Methods 5,632 patients (mean age 60.2 + 11.8 years, 36.5% female) from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry were followed over the course of 5 years. Obstructive CAD was defined as ≥50% luminal stenosis in a coronary vessel. Using Cox proportional-hazards models, we calculated the hazard ratio (HR) for incident MACE among women and men, defined as death or myocardial infarction (MI). Results Obstructive CAD was more prevalent in men (42% vs. 26%, p<0.001) whereas women were more likely to have normal coronary arteries (43% vs. 27%, p<0.001). There were a total of 798 incident MACE events. After adjustment, there was a strong association between increased MACE risk and non-obstructive CAD (HR 2.16 for women, 2.56 for men, p<0.001 for both), obstructive one-vessel CAD (HR 3.69 and 2.66, p<0.001), two-vessel CAD (HR 3.92 and 3.55, p<0.001) and three-vessel/left-main CAD (HR 5.94 and 4.44, p<0.001). Further exploratory analyses of atherosclerotic burden did not identify gender-specific patterns predictive of MACE. Conclusion In a large prospective CCTA cohort followed long-term, we did not observe an interaction of gender for the association between MACE risk and increased per-vessel extent of obstructive CAD. These findings highlight the persistent prognostic significance of anatomic CAD subsets as detected by CCTA for the risk of MACE in both women and men.

Objective To examine long-term prognosis of a zero coronary artery calcium (CAC) score among asymptomatic individuals and its associated warranty period. Background Emerging evidence supports CAC=0 as a favorable cardiovascular short-to-intermediate term prognostic factor. Methods 9715 individuals undergoing CAC imaging were stratified by age, Framingham risk score (FRS) and Adult Treatment Panel III (NCEP ATP III) categories and followed for a mean of 14.6 (12.9–16.8) years. Cox regression, area under the receiver operating characteristic curve (AUC) and net reclassification information (NRI) were used to assess all-cause mortality, discrimination and reclassification of CAC=0 compared with FRS and NCEP ATP III, respectively. A warranty period was pre-defined as <1% annual mortality rate. Vascular age was estimated by linear regression. Results Among 4864 individuals with baseline CAC=0 (mean age 52.1±10.8 years; 57.9% male), 229 deaths occurred. The warranty period of CAC=0 was almost 15 years for individuals at low and intermediate risk with no significant differences regarding age and gender. CAC=0 was associated with a vascular age of 1, 10, 20, and 30 years below chronologic age for individuals between 50–59, 60–69, 70–79, and ≥80 years, respectively. CAC score was the strongest predictor of death (HR 2.67, 95% CI 2.29–3.11) that enabled discrimination and consistent reclassification beyond FRS (AUC 0.71 vs. 0.64, p<0.001) and NCEP ATP III (AUC 0.72 vs. 0.64, p<0.001). Conclusions CAC=0 confers a 15-year warranty period against mortality among individuals at low-to-intermediate risk, which is unaffected by age or gender. Furthermore, in individuals considered at high-risk by clinical risk scores the presence of CAC=0 confers better survival than in individuals at low-to-intermediate risk but with any CAC.

Background-Cardiovascular screening of women using traditional risk factors has been challenging, with results often classifying a majority of women as lower risk than men. The aim of this report was to determine the long-term prognosis of asymptomatic women and men classified at low-intermediate risk undergoing screening with coronary artery calcium (CAC) scoring. Methods and Results-A total of 2363 asymptomatic women and men with traditional risk factors aggregating into a lowintermediate Framingham risk score (6%-9.9%; 10-year predicted risk) underwent CAC scanning. Individuals were followed up for a median of 14.6 years. We estimated all-cause mortality using Cox proportional hazards models; hazard ratios with 95% confidence intervals were calculated. The area under the curve from a receiver operating characteristics curve analysis was calculated. There were 1072 women who were older (55.6 years) when compared with the 1291 men (46.7 years; P<0.0001), resulting in a greater prevalence and extent of CAC; 18.8% of women and 15.1% of men had a CAC score ≥100 (P=0.029). This older group of women had a 1.44-fold higher 15-year adjusted mortality hazard when compared with men (P=0.022). For women, the 15-year mortality ranged from 5.0% for those with a CAC score of 0 to 23.5% for those with a CAC score ≥400 (P<0.001). For men, the 15-year mortality ranged from 3.5% for those with a CAC score of 0 to 18.0% for those with a CAC score ≥400 (P<0.001). Women with CAC scores >10 had a higher mortality risk when compared with men. Conclusions-Our findings extend previous work that CAC effectively identifies high-risk women with a low-intermediate risk factor burden. These data require validation in external cohorts but lend credence to the use of CAC in women to improve risk detection algorithms that are currently based on traditional risk factors. (Circ Cardiovasc Imaging. 2016;9:e003742.