Impact of pre-operative statin use on risk of mortality and early atrial fibrillation after heart transplantation.

BACKGROUND: Pre-operative statin use has shown to reduce the incidence of post-operative atrial fibrillation (AF), but not mortality in patients undergoing cardiac surgery. This association, however, has not been examined in a heart transplant (HT) cohort. METHODS: Adults (≥18 yr) who underwent HT between 1997 and 2007 at the University of Minnesota were retrospectively identified. Primary outcome was 30-d mortality after HT. Secondary outcomes were 30-d incidence of AF and time to all-cause mortality. RESULTS: Data from 259 patients (mean age 52.0 ± 11.7 yr, 81% males) were analyzed. Total of 133 (51%) patients were on statin pre-operatively at the time of HT and constituted the statin group. During a mean follow-up of 6.7 ± 3.7 yr, 82 (32%) deaths occurred, 21 (8%) of which occurred within 30 d of HT. The incidence of 30-d mortality was not significantly different between the statin and no-statin groups (9% vs. 7%, p = 0.58). Further, cumulative long-term survival after HT was not significantly different between the study groups (log-rank p = 0.49). Pre-transplant statin use did not impact the 30-d incidence of post-transplant AF (16% vs. 19%, p = 0.59). CONCLUSIONS: Pre-operative statin therapy does not seem to influence the risk of mortality or early post-operative AF after HT. Future large-scale studies are required to validate these preliminary findings.

Mortality prediction using a modified Seattle Heart Failure Model may improve patient selection for ventricular tachycardia ablation.

BACKGROUND: Catheter ablation is frequently used as a palliative option to reduce shock burden in patients with ventricular tachycardia (VT). A risk prediction tool that accurately predicts short-term survival could improve patient selection for VT ablation. OBJECTIVE: The objective of the study is to assess utility of the Seattle Heart Failure Model (SHFM) to predict 6-month mortality in patients undergoing VT ablation. METHODS: Data on patients who underwent VT ablation at 2 tertiary institutions were retrospectively compiled. The SHFM score at the time of ablation, including 2 added VT variables, was used to predict 6-month mortality. The predicted number of deaths was compared to the observed number to assess model calibration. Model discrimination of those who died within 6 months was assessed by both K- and C-statistics. RESULTS: Mean age of the 243 patients was 63 ± 12 years; 89% were male. Mean SHFM score for the cohort was 1.3 ± 1.3. The Kaplan-Meier probability of death within 6 months was 14% (34 patients). The number of deaths estimated by the SHFM at 6 months was 31 (13%) giving a predicted to observed ratio of 0.91 (95% CI 0.64-1.30). The K-statistic for 6-month mortality predictions was 0.77 (95% CI 0.73-0.81), whereas the C-statistic was 0.84 (95% CI 0.78-0.92). Patients with an SHFM score ≥4.0 had an estimated positive predictive value of 80% (95% CI 28%-99%) for dying within 6 months of VT ablation. CONCLUSION: The SHFM was well calibrated to a sample of patients who underwent VT ablation and provided good discrimination of short-term deaths. This model could be useful as a prognostic tool to improve patient selection for VT ablation.

Impact of renal dysfunction on the Seattle Heart Failure Model.

BACKGROUND: Renal dysfunction (RD) is a strong predictor of mortality in patients with heart failure (HF). However, its impact on the discrimination of the Seattle Heart Failure Model (SHFM) is poorly understood. METHODS: Serum creatinine (SCr) and creatinine clearance (CrCl) were reviewed for patients from four of the six cohorts originally used to derive and validate the SHFM. Patients were followed for death. The independent prediction of adding SCr or CrCl to the SHFM was assessed using multivariable Cox proportional hazards and the incremental value for prediction by changes in the ROC curves for 1- and 2-year event prediction. RESULTS: Among 7,146 patients (mean age 63 ± 11 years), 1,511 deaths occurred during a mean follow-up of 2.04 years. SCr and CrCl had a modest positive correlation with SHFM (r = 0.30, p = 0.002). In combination with SHFM, SCr (hazard ratio [HR] per mg/dl 1.25, 95% CI 1.13 to 1.38, p < 0.0001) and CrCl (HR per 10 ml/min 0.95, 95% CI 0.93 to 0.97, p < 0.0001) were both multivariable predictors of events. When stratified by absolute risk based on the SHFM, SCr or CrCl provided more additional information in lower risk patients and less or no additional information in higher risk patients. The addition of SCr and the SHFM*SCr, or CrCl and the SHFM*CrCl interaction to the SHFM was associated with almost no change in the 1- and 2-year area under ROC curves for the SHFM score. CONCLUSIONS: Compared with the SHFM alone, RD is independently predictive of mortality only in lower risk patients. Overall discrimination is only minimally improved with addition of SCr or CrCl to the SHFM.

Waist circumference and metabolic syndrome: the risk for silent coronary artery disease in males.

BACKGROUND: Waist circumference (WC) is a component used to define metabolic syndrome. However, its role as an independent predictor of silent coronary artery disease (CAD), above its contribution to metabolic syndrome, remains unknown. METHODS: Male veterans without known CAD, undergoing cardiac stress testing for indications other than typical angina or its equivalent, were evaluated for the presence of silent CAD. High WC and metabolic syndrome were defined per the revised National Cholesterol Education Program (NCEP-R) and the International Diabetes Federation (IDF) criteria. RESULTS: Data on 1,071 patients (age 61±11 years) were analyzed retrospectively. On multivariable logistic regression analysis [odds ratio (OR), 95% confidence interval (CI), P value), a WC ≥94 cm (1.42, 1.04-1.93; P=0.026), metabolic syndrome by NCEP-R (1.73, 1.29-2.33; P<0.0001), and metabolic syndrome by IDF (1.57, 1.17-2.11; P=0.003) were independent predictors of silent CAD. When comparing patients meeting criteria for metabolic syndrome defined by either NCEP-R or IDF, the prevalence of silent CAD was not statistically different (P=0.86). The prevalence of silent CAD associated with a high WC was not inferior to that seen between silent CAD and metabolic syndrome as defined by either criterion. Last, among patients with metabolic syndrome defined by NCEP-R, those with a high WC as a defining component of metabolic syndrome had a higher prevalence of silent CAD (30% vs. 20%; P=0.026). CONCLUSION: A WC ≥94 cm in males is independently associated with an increased prevalence of silent CAD. In patients with metabolic syndrome, this prevalence is increased by the presence of high WC.

A retrospective analysis of proceduralist-directed, nurse-administered propofol sedation for implantable cardioverter-defibrillator procedures.

BACKGROUND: There is controversy whether proceduralist-directed, nurse-administered propofol sedation (PDNAPS) is safe. OBJECTIVE: To assess the frequency of adverse events when PDNAPS is used for implantable cardioverter-defibrillator (ICD)-related procedures and to determine the patient and procedural characteristics associated with adverse events. METHODS: Consecutive ICD-related procedures using PDNAPS from May 2006 to July 2009 at a tertiary-care hospital were evaluated. Serious adverse events were defined as procedural death, unexpected transfer to an intensive care unit, respiratory failure requiring intubation/bag-mask ventilation, or hypotension requiring vasoconstrictor/inotrope support. Nonserious adverse events were defined as hypotension requiring fluid resuscitation or hypoxemia requiring augmented respiratory support with non-rebreather mask, oral airway, or jaw lift. RESULTS: Of 582 patients (age 64 ± 14 years, 72.3% males) undergoing ICD-related procedures using PDNAPS, 58 (10.0%) patients had serious adverse events with no procedural death and 225 (38.7%) had nonserious adverse events. Longer procedure duration (relative risk [RR] = 2.1 per hour; 95% confidence interval [CI] = 1.6-2.8; P < .001) and biventricular implant (RR = 2.7; CI = 1.4-5.3; P = .003) were independent predictors of serious adverse events. A longer procedure duration (RR = 1.4 per hour; CI = 1.1-1.7; P = .001), heart failure class (RR = 1.4 per 1 class; CI = 1.1-1.7; P = .002), and use of propofol infusion (RR = 3.5; CI = 2.2-5.7; P < .001) were independent predictors of nonserious adverse events. CONCLUSION: PDNAPS for shorter ICD procedures including single- and dual-chamber implants, generator changes, and defibrillation threshold testing have acceptable rates of serious adverse events and manageable nonserious adverse events and should be considered for further study. Biventricular implants and other complex procedures should be done with an anesthesiologist.