The prognostic value of cardiac computed tomographic angiography

PCI Alternative Using Sustained Exercise (PAUSE): Rationale and trial design

Cardiovascular disease (CVD) currently claims nearly one million lives yearly in the US, accounting for nearly 40% of all deaths. Coronary artery disease (CAD) accounts for the largest number of these deaths. While efforts aimed at treating CAD in recent decades have concentrated on surgical and catheter-based interventions, limited resources have been directed toward prevention and rehabilitation. CAD is commonly treated using percutaneous coronary intervention (PCI), and this treatment has increased exponentially since its adoption over three decades ago. Recent questions have been raised regarding the cost-effectiveness of PCI, the extent to which PCI is overused, and whether selected patients may benefit from optimal medical therapy in lieu of PCI. One alternative therapy that has been shown to improve outcomes in CAD is exercise therapy; exercise programs have been shown to have numerous physiological benefits, and a growing number of studies have demonstrated reductions in mortality. Given the high volume of PCI, its high cost, its lack of effect on survival and the potential for alternative treatments including exercise, the current study is termed "PCI Alternative Using Sustained Exercise" (PAUSE). The primary aim of PAUSE is to determine whether patients randomized to exercise and lifestyle intervention have greater improvement in coronary function and anatomy compared to those randomized to PCI. Coronary function and anatomy is determined using positron emission tomography combined with computed tomographic angiography (PET/CTA). Our objective is to demonstrate the utility of a non-invasive technology to document the efficacy of exercise as an alternative treatment strategy to PCI.

Characterization of culprit lesions in acute coronary syndromes compared with stable angina pectoris by dual-source computed tomography

To identify the characterization of culprit lesions in acute coronary syndrome (ACS) compared with stable angina pectoris (SAP) by dual-source computed tomography (DSCT). 65 patients with ACS and 75 controls with SAP and a similar atherosclerotic risk profile were studied. Computed tomography (CT) coronary angiography was performed using a DSCT scanner before invasive catheterization. Using DSCT and quantitative coronary angiography (QCA), lesion characteristics [luminal cross-section area (L-CSA), vascular cross-section area (V-CSA), plaque area and degree of stenosis) were detected. Plaque types, mean and minimum CT density (Hounsfield Unit; HU), remodeling index, and presence of "spotty" calcifications were analyzed using DSCT. A good correlation was observed between DSCT and QCA for all lesion characteristics (P < 0.05). Culprit lesions in ACS had much larger V-CSA (20.5 ± 6.0 vs. 14.8 ± 4.8 mm(2)), plaque area (15.3 ± 5.0 vs. 11.1 ± 3.3 mm(2)) and remodeling index (1.3 ± 0.2 vs. 1.0 ± 0.4) than stable lesions in SAP (P < 0.05). The prevalence of non-calcified/calcified/mixed plaque was 30/0/35 in ACS versus 25/15/35 stable lesions in SAP (P < 0.01). The proportion of "spotty" calcified plaques was 21.5 % in culprit lesions (14 of 65) versus 1.3 % in SAP (1 of 75). The mean/minimum HU of culprit lesions was 88.6 ± 43.2/154.2 ± 98.7 in ACS versus 45.9 ± 34.7/98.2 ± 76.8 in SAP (both P < 0.01). DSCT is a feasible means of detecting coronary stenosis with good accuracy compared with QCA. Culprit lesions in ACS display a greater proportion of non-calcified material with lower CT attenuation, "spotty" calcifications and higher remodeling index compared with SAP lesions.

Prognostic value of absence or presence of coronary artery disease determined by 64-slice computed tomography coronary angiography a systematic review and meta-analysis

To determine via a meta-analysis the prognostic value of 64-slice computed tomography angiography (CTA) by quantifying risk of major adverse cardiac events (MACE) in different patient groups classified according to CT angiographic findings. A systematic literature search and meta-analyses was conducted on 10 studies examining stable, symptomatic and intermediate risk patients by 64-slice CTA. Patients were followed up for a mean of 21 month. Patient groups with CT-angiographic non-obstructive (stenosis <50% of luminal narrowing) or obstructive (stenosis ≥50% of luminal narrowing) CAD were compared to those having normal angiography without CAD. MACE (cardiac death, non-fatal myocardial infarction and revascularization) numbers were used to calculate odds ratios (OR) with 95% confidence interval (CI) in each group. Ten studies including 5,675 patients were eligible for meta-analysis. The cumulative MACE rate over 21 months were 0.5% in patients with normal CTA, 3.5% in non-obstructive CAD and 16% in obstructive CAD. Compared to normal CTA, non-obstructive CAD was associated with significant increased risk of MACE with OR=6.68 (3.01-14.82 CI 95%), P=0.0001. Obstructive CAD was associated with further significant increased risk of MACE with OR=41.19 (22.56-75.18, CI 95%), P=0.0001. The studies were homogenous, P-value >0.05 for heterogeneity. 64-slice CTA is able to differentiate low-risk from high-risk patients with suspected or known CAD. Absence of CAD predicts excellent prognosis, while obstructive CAD is associated with markedly increased risk of MACE.