Renal dysfunction in congestive heart failure, pathophysiological and prognostic significance.

AIMS: Many congestive heart failure (CHF) patients suffer from various comorbidities, which may aggravate CHF or independently increase mortality risk. Renal failure (RF) is one of them. We defined bedside clinical, laboratory and electrocardiographic parameters characterizing CHF patients with and without concomitant RF, and analyzed their impact on mortality. METHODS: We studied symptomatic unselected consecutive furosemide-treated CHF patients hospitalized for various acute conditions. On admission, history taking, physical examination, chest x-ray, ECG and routine laboratory tests were performed. Subsequently, patients were divided into 2 subgroups, those with serum creatinine > or = 1.5 mg/dl (RF) and those with lower values. Following discharge, information concerning mortality and circumstance of death was obtained from hospital records and outpatient death certificates. RESULTS: Included were 398 patients, 163 (40.9%) with RF and 235 free of RF. Prevailing in the RF subgroup were older age (mean age 75.5 vs 70.8, p < 0.001), male gender (p < 0.001), admission pulmonary edema (p = 0.007), cardiac arrhythmias (p = 0.05), cardiac conduction disturbances (p = 0.002), severe CHF (p = 0.005), lower ejection fraction (p = 0.03), anemia (p = 0.009), higher furosemide maintenance dosages (p < 0.001), insulin treatment (p = 0.03) and receiving less ACE inhibitors (p = 0.006). On median follow-up of 43 months, mortality was 54.9% in the RF vs 31.9% in the non-RF subgroup (p < 0.001), RF being the parameter most significantly associated with low survival (OR 1.97, p < 0.001). In the RF subgroup older age (p < 0.02), female gender (p < 0.003) and not using ACE inhibitors (p = 0.04) or drugs with antiarrhythmic effects (p < 0.005), emerged significantly associated with low survival, while diabetes mellitus (DM) and admission pulmonary edema tended to be so associated (p < 0.2). Using multivariate analysis in the RF subgroup, older age, female gender and DM proved most significantly associated with poorer survival (p = 0.004, OR 1.5, p = 0.03, OR 1.72, p = 0.04, OR 1.28, respectively). In the non-RF subgroup, only older age (p = 0.005) and DM (p = 0.05) were significantly associated with low survival. Sudden death occurred in 21 patients, 14 (8.6%) in the RF and 7 (3%) in the non-RF subgroup (p < 0.001). CONCLUSIONS: RF is a marker of severity in CHF. Its full-blown deleterious prognostic effect is already manifested at serum creatinine 1.5 mg/dl. Older age, DM and female gender most significantly heralded a shorter survival. Such patients require special care.

Serum magnesium aberrations in furosemide (frusemide) treated patients with congestive heart failure: pathophysiological correlates and prognostic evaluation.

OBJECTIVES: To determine the prevalence of hypomagnesaemia and hypermagnesaemia, to discern various factors associated with abnormal serum magnesium, and to estimate prognostic significance of serum magnesium aberrations in patients with congestive heart failure. DESIGN: Observational study. SETTING: Medical department of a university hospital (tertiary referral centre). PATIENTS: 404 consecutive patients admitted with congestive heart failure as one of the diagnoses and previously treated with furosemide (frusemide) for at least three months. MAIN OUTCOME MEASURES: Clinical, biochemical, and electrocardiographic variables were analysed with respect to serum magnesium aberrations. Following discharge, mortality rates, including sudden death, were registered. RESULTS: Hypomagnesaemia was found in 50 patients (12.3%) and 20 (4.9%) were hypermagnesaemic. Female sex (p < 0.04), diabetes mellitus (p < 0.006), hypocalcaemia (p = 0.03), hyponatraemia (p < 0.05), malignant disease (p = 0.05), and high fever (p = 0.05) were statistically associated with hypomagnesaemia. Renal failure, severe congestive heart failure, and high dose furosemide treatment (> 80 mg/day) were associated with hypermagnesaemia (p < 0.001, p = 0.05, and p < 0.03, respectively). Hypermagnesaemic patients were older and weighed less. On follow up (median duration 43 months), 169 (41.8%) died, with 22 (13%) sudden deaths. Mortality was highest with hypermagnesaemia, lowest with normomagnesaemia, and intermediate with hypomagnesaemia. After adjustment for renal failure, old age, and severity of congestive heart failure, hypomagnesaemia but not hypermagnesaemia emerged as being significantly associated with shorter survival (p = 0.009). No statistical association was found between sudden death and magnesium concentrations. CONCLUSIONS: While hypermagnesaemia seems to represent a prognostic marker only, hypomagnesaemia appears to have an adverse pathophysiological effect. The subgroup of patients at risk for hypomagnesaemia requires frequent serum magnesium determinations and magnesium replacement for as long as hypomagnesaemia persists.

Adequacy of anticoagulation in patients with atrial fibrillation: effect of various parameters.

BACKGROUND: Despite reported evidence of the vital importance of appropriate anticoagulation in patients with chronic atrial fibrillation for stroke prevention, this treatment modality still lags behind optimal requirements. HYPOTHESIS: Our objectives were to evaluate various doctor or patient-related factors that influence quality of control and to assess the adequacy of anticoagulation provided by physicians in the community. METHODS: In a retrospective study, International Normalized Ratio (INR) values obtained immediately on admission to hospital were considered representative of previous long-term control. RESULTS: Only 42% of the relevant 385 patient population fell within the protective anticoagulation range of INR 1.91-4.1. The respective figures for patients with poor (INR < 1.5) or suboptimal (INR 1.51-1.9) control, as well as those whose INR values risked bleeding (INR > 4.1), were 28.3, 14.1, and 15.6%. Patient involvement in treatment positively influenced quality of control. By contrast, age 70-80 years or absence of congestive heart failure negatively affected quality of anticoagulation [p = 0.07, odds ratio (OR), 1.7 (95% confidence interval. 0.94-3.08), p = 0.014, OR, 2.06 (95% confidence interval, 1.15-3.7) respectively]. The percentage of patients admitted with stroke who had been adequately anticoagulated was significantly lower than that of patients who had no stroke (21 vs. 44.4%). Adequacy of anticoagulation in patients with cardiac prosthetic valves was superior compared with the rest of the patient population (56.7 vs. 42% with optimal, and only 14.5 vs. 28.3% with poor anticoagulation, respectively), indicating that under the same conditions a better quality of treatment could be achieved. CONCLUSIONS: Adequacy of anticoagulation in patients with atrial fibrillation lags behind actual recommendations. Better control is required and achievable.

Warfarin for stroke prevention still underused in atrial fibrillation: patterns of omission.

BACKGROUND AND PURPOSE: The value of warfarin in preventing stroke in patients with chronic atrial fibrillation is well established. However, the prevalence of such treatment generally lags behind actual requirements. The aim of this study was to evaluate doctor- and/or patient-related demographic, clinical, and echocardiographic factors that influence decision for warfarin treatment. METHODS: Between 1990 and 1998, 1027 patients were discharged with chronic or persistent atrial fibrillation. This population was composed of (1) patients with cardiac prosthetic valves (n=48), (2) those with increased bleeding risks (n=152), (3) physically or mentally handicapped patients (n=317), and (4) the remaining 510 patients, the main study group who were subjected to thorough statistical analysis for determining factors influencing warfarin use. RESULTS: The respective rates of warfarin use on discharge in the 4 groups were 93.7%, 30.9%, 17.03%, and 59.4% (P=0.001); of the latter, an additional 28.7% were discharged on aspirin. In the main study group, warfarin treatment rates increased with each consecutive triennial period (29.7%, 53.6%, and 77.1%, respectively; P=0.001). Age >80 years, poor command of Hebrew, and being hospitalized in a given medical department emerged as independent variables negatively influencing warfarin use: P=0.0001, OR 0.30 (95% CI 0.17 to 0.55); P=0.02, OR 0.59 (95% CI 0.36 to 0.94); and P=0.0002, OR 0.26 (95% CI 0.12 to 0.52), respectively. In contrast, past history of stroke and availability of echocardiographic information, regardless of the findings, each increased warfarin use (P=0.03, OR 1.95 [95% CI 1.04 to 3.68], and P=0.0001, OR 3.52 [95% CI 2.16 to 5.72], respectively). CONCLUSIONS: Old age, language difficulties, insufficient doctor alertness to warfarin benefit, and patient disability produced reluctance to treat. Warfarin use still lags behind requirements.