Predictive value of myocardial perfusion single-photon emission computed tomography and the impact of renal function on cardiac death.

BACKGROUND: Patients with chronic kidney disease (CKD) have worse cardiovascular outcomes than those without CKD. The prognostic utility of myocardial perfusion single-photon emission CT (MPS) in patients with varying degrees of renal dysfunction and the impact of CKD on cardiac death prediction in patients undergoing MPS have not been investigated. METHODS AND RESULTS: We followed up 1652 consecutive patients who underwent stress MPS (32% exercise, 95% gated) for cardiac death for a mean of 2.15+/-0.8 years. MPS defects were defined with a summed stress score (normal summed stress score <4, abnormal summed stress score>or=4). Ischemia was defined as a summed stress score >or=4 plus a summed difference score >or=2, and scar was defined as a summed difference score <2 plus a summed stress score >or=4. Renal function was calculated with the Modified Diet in Renal Disease equation. CKD (estimated glomerular filtration rate <60 mL . min(-1) . 1.73 m(-2)) was present in 36%. Cardiac death increased with worsening levels of perfusion defects across the entire spectrum of renal function. Presence of ischemia was independently predictive of cardiac death, all-cause mortality, and nonfatal myocardial infarction. Patients with normal MPS and CKD had higher unadjusted cardiac death event rates than those with no CKD and normal MPS (2.7% versus 0.8%, P=0.001). Multivariate Cox proportional hazards models revealed that both perfusion defects (hazard ratio 1.90, 95% CI 1.47 to 2.46) and CKD (hazard ratio 1.96, 95% CI 1.29 to 2.95) were independent predictors of cardiac death after accounting for risk factors, left ventricular dysfunction, pharmacological stress, and symptom status. Both MPS and CKD had incremental power for cardiac death prediction over baseline risk factors and left ventricular dysfunction (global chi(2) 207.5 versus 169.3, P<0.0001). CONCLUSIONS: MPS provides effective risk stratification across the entire spectrum of renal function. Renal dysfunction is also an important independent predictor of cardiac death in patients undergoing MPS. Renal function and MPS have additive value in risk stratisfying patients with suspected coronary artery disease. Patients with CKD appear to have a relatively less benign prognosis than those without CKD, even in the presence of a normal scan.

Quality of life associated with daily opioid therapy in a primary care chronic pain sample.

BACKGROUND: Daily opioid therapy is widely used in the treatment of chronic noncancer pain, yet there is limited empirical evidence on the relationship of opioid dosing and health-related quality of life (HRQoL) in primary care settings. METHODS: An analysis was conducted to assess the relationship of opioid dose to quality of life. The sample consisted of 801 chronic pain patients who were prescribed daily opioids and 93 nonopioid users recruited from the practices of 235 primary care physicians. Eight HRQoL domain scores were calculated and compared with US norms and across opioid use groups. A new modeling technique, propensity score matching analysis, was performed to adjust for potential confounding factors across 4 morphine-equivalent opioid dose groups (<20 mg, 20-40 mg, 41-105 mg, >105 mg). RESULTS: HRQoL scores were significantly lower in chronic noncancer pain patients relative to the US general population regardless of opioid use. In unadjusted comparisons, those using up to 20 mg/d of opioids had the highest HRQoL scores, whereas those using >105 mg/d had the lowest. After adjusting for potential confounders, those in the 20 mg to 40 mg/d dosing group had significantly better HRQoL scores than their nonopioid-treated or higher dosed counterparts. CONCLUSION: Use of low- to moderate-dose opioid therapy provides an improvement in HRQoL scores for chronic noncancer pain patients compared to no opioid therapy, while high-dose opioids have a smaller positive effect that is limited to mental health quality of life and patient satisfaction, and that may not justify treatment.

Alcohol biomarker screening in medical and surgical settings.

This article highlights the proceedings of a symposium presented at the 28th Annual Meeting of the Research Society on Alcoholism in Santa Barbara, CA, on June 28, 2005, organized and chaired by Peter Miller. The presentations included (1) Screening for Alcohol Use Disorders in Surgical and Trauma Patients, presented by Claudia Spies; (2) Are Serum Levels of %CDT and GGT Related to Severity of Liver Biopsy Inflammation, Fibrosis, and Steatohepatitis in Patients with Hepatitis C? by Martin Javors; (3) Biochemical Alcohol Screening in the Treatment of Hypertension, presented by Peter Miller; and (4) The Cost-Effectiveness of a New Biomarker, CDT, in a Primary Care Sample, by Michael Fleming. Presentations were discussed by Raymond Anton.

Cost-benefit analysis of a new alcohol biomarker, carbohydrate deficient transferrin, in a chronic illness primary care sample.

BACKGROUND: Carbohydrate Deficient Transferrin (CDT) is a new alcohol biomarker recently approved by the Food and Drug Administration for alcohol screening. Limited information is available on the economic benefits of alcohol biomarkers. Our objective was to conduct a cost-benefit analysis (CBA) of the CDT test in a primary care sample of patients being treated for diabetes and hypertension. METHODS: A decision tree was created using data from national surveys, published literature, and two brief intervention trials conducted in primary care settings. The decision tree was used to estimate the costs and benefits of CDT under different scenarios. RESULTS: For the base case, utilizing CDT in addition to patient self-report resulted in an increase from 28 to 53 problem drinking cases identified out of 70 cases screened. With increased detection and subsequent intervention, the average medical and legal costs were far lower in the CDT arm of the study. When these avoided costs were incorporated into the model, an overall savings of $212.30 per patient was realized with CDT testing. Monte Carlo analysis also indicated a trend toward cost savings, with a mean cost savings of approximately $353 and a range of $1,619 in savings to $450 in costs for 1,000 simulations of the decision tree model. CONCLUSION: This CBA suggests that the addition of routine CDT screening to patient self-report may provide positive net economic benefits in primary care settings.