Coronary fractional flow reserve.

OBJECTIVE. This article presents the basic definitions and concepts of fractional flow reserve (FFR), a focused understanding of the need for hyperemia during assessment, key clinical studies supporting its use, and an introduction to newer noninvasive methods using FFR CT. CONCLUSION. Although it is still a new procedure, FFR CT may prove to be of tremendous use as the computational processing improves to reduce calculation times and enhance accuracy.

Total and individual coronary artery calcium scores as independent predictors of mortality in hemodialysis patients.

Many traditional and nontraditional risk factors contribute to vascular calcification among maintenance hemodialysis (MHD) patients. It is not clear whether coronary artery calcification (CAC) delineates a higher mortality risk independent of known risk factors. We examined 6-year (10/2001-9/2007) survival of 166 MHD patients, aged 53 +/- 13 years, with baseline CAC scores. Patients were grouped into four CAC groups: 0, 1-100, 101-400, and 400+. The 101-400 and 400+ groups were associated with a significantly higher adjusted risk of death than CAC 0 with hazard ratios (HR) 8.5 (95% CI: 1.1-48.1, p = 0.02) and 13.3 (95% CI: 1.3-65.1, p = 0.01), respectively, independent of demographics, comorbidity, lipids and other cardiovascular risks, surrogates of bone disease, nutritional and inflammatory markers and dialysis dose. Total CAC [HR 6.7 (1.1-21.5, p = 0.03)] followed by the presence of CAC in the left main [4.6 (2.2-9.8, p = 0.001)] and left anterior descending artery [4.3 (2.1-14.2, p = 0.001)] were strong independent predictors of mortality even after adjusting for above covariates. Total and vessel-specific CAC predict mortality in MHD patients independent of traditional and nontraditional risk factors.

Associations of body fat and its changes over time with quality of life and prospective mortality in hemodialysis patients.

BACKGROUND: In maintenance hemodialysis (MHD) patients, a larger body size is associated with better survival but a worse self-reported quality of life (QoL). It is not clear whether muscle mass or body fat confers the survival advantage. OBJECTIVE: We hypothesized that both a low baseline body fat percentage and a loss of fat over time were independently associated with higher mortality but with a better QoL score. DESIGN: In 535 adult MHD patients, body fat was measured directly with the use of near infrared interactance and QoL was measured with a Short Form 36 questionnaire. The patients were followed for < or =30 mo. RESULTS: Across four 12% increments of body fat at baseline, the reported QoL scores were progressively lower (P < 0.01). After a multivariate adjustment for demographics and surrogates of muscle mass and inflammation (ie, midarm muscle circumference, serum creatinine, and proinflammatory cytokines), 46 patients with body fat of <12% had a death hazard ratio (HR) 4 times that of 199 patients with body fat content between 24% and 36% (HR: 4.01; 95% CI: 1.61, 9.99; P = 0.003). In 411 MHD patients whose body fat was remeasured after 6 mo, a fat loss (< or =-1%) was associated with a death risk 2 times that of patients who gained fat (> or =1%) after a multivariate adjustment (HR: 2.06; 95% CI: 1.05, 4.05; P = 0.04). CONCLUSIONS: A low baseline body fat percentage and fat loss over time are independently associated with higher mortality in MHD patients even after adjustment for demographics and surrogates of muscle mass and inflammation, whereas a tendency toward a worse QoL is reported by MHD patients with a higher body fat percentage. Obesity management in dialysis patients may need reconsideration.