Anti-thrombotic strategies for patients with atrial fibrillation and heart failure

[Neurological aspects of chronic heart failure]

Chronic heart failure (CHF) is one of the leading causes of hospitalization, morbidity and mortality. Moreover, there is a high rate of neurological as well as neuropsychological comorbidities, namely ischemic stroke, structural brain alterations, cognitive impairment, sleep apnea and possible side-effects of HF medication such as delirium or (intracerebral) hemorrhage. The higher stroke risk in patients with HF increases further with age, concomitant arterial hypertension or atrial fibrillation (AF). In women the stroke risk increases with reduced ejection fraction (EF). In general stroke in HF patients is associated with a poor outcome and higher mortality, which is increased more than 2-fold. Furthermore, approximately 25-80% of all patients with CHF experience cognitive impairments such as decreased attention and concentration, memory loss, diminished psychomotor reaction time and decreased executive functions. Cognitive impairment in patients with HF has been linked to losses in gray matter, (silent) ischemic strokes, decreased cerebral perfusion and higher mortality. Moreover, sleep apnea occurs in more than half of all patients with CHF and reduced EF. However, prospective studies are needed to test whether early detection and optimal treatment of HF reduces the burden of neurological and neuropsychological sequelae.

The incidence of ischemic stroke in chronic heart failure: a meta-analysis

BACKGROUND

There is marked variability in the reported stroke rates among persons with heart failure (HF). We performed a meta-analysis to provide summary estimates of the stroke rate in HF and to explain heterogeneity in the existing literature. We will summarize the ischemic stroke rate at various time points during follow-up among adults with chronic heart failure.

METHODS AND RESULTS

A systematic review of the electronic literature in Medline and PubMed as well as hand searching of the reference lists of identified articles and of the meeting abstracts for the 1995-2004 American College of Cardiology and American Heart Association scientific sessions was performed to identify qualifying studies. Articles were included if they included a population with chronic HF and reported the number (or percent) of persons with HF who experienced an ischemic stroke during follow-up. Studies were excluded if the study population included > or = 50% of persons with acute (postmyocardial infarction) HF, or if > or = 50% of the study population required artificial support with a ventricular assist device or parenteral inotropic medications. Case reports, case series, and nonoriginal research articles were not included. Determination of study eligibility and data extraction were conducted by 2 independent reviewers using standardized forms. Results are reported as stroke rate per 1000 cases of HF, with 95% Poisson confidence intervals. Pooled estimates of the stroke rate were calculated with fixed and random effects models. Heterogeneity was explored according to a priori specified subgroup analyses. Overall, 26 studies met inclusion criteria. Eighteen of every 1000 persons suffered a stroke during the first year after the diagnosis of HF. The stroke rate increased to a maximum of 47.4 per 1000 at 5 years. Studies with fewer women, those conducted in 1990 or earlier, and cohort studies reported higher stroke rates than studies with more women, those conducted after 1990, and clinical trials.

CONCLUSIONS

Stroke is an important complication among persons with HF. Variability among reported stroke rates can be explained in part by differences in study design, patient population, and HF standards of care at the time of the study. Despite the heterogeneity in reported stroke rates, this meta-analysis shows that stroke prevention in HF represents an opportunity to prevent morbidity and save many lives in this highly fatal disease.

ANTICOAGULATION WITH WARFARIN IN VITREORETINAL SURGERY

PURPOSE

To describe the clinical course of patients undergoing vitreoretinal procedures while receiving systemic anticoagulation with warfarin.

METHODS

We reviewed patient demographics, ocular findings, and clinical courses for 25 patients receiving systemic anticoagulation with warfarin who subsequently underwent vitreoretinal surgery.

RESULTS

Patient ages ranged from 49 years to 81 years (median, 69 years). Indications for anticoagulation included atrial fibrillation, cerebrovascular disease, deep vein thrombosis, prosthetic heart valves, and hypercoagulable state. Follow-up ranged from 4 months to 36 months (median, 19.5 months). The international normalized ratio ranged from 1.5 to 3.1 (median, 2.0). Final vision after surgery ranged from 20/20 to 20/400 (median, 20/100). One patient who underwent scleral buckling and external drainage of subretinal fluid had an intraoperative subretinal hemorrhage associated with the drainage procedure. In all other patients, no intraoperative complications occurred.

CONCLUSION

Cessation of therapy with warfarin may not be necessary in patients receiving anticoagulation who are undergoing vitreoretinal procedures. Successful visual and anatomical results may be achieved after vitreoretinal surgery for patients receiving anticoagulation with warfarin. The management of anticoagulation should occur in conjunction with the patient's internist to allow a clear understanding of the potential systemic risks of cessation of warfarin treatment preoperatively.

Ischemic stroke after heart failure: a community-based study

BACKGROUND

Although studies have examined the incidence of stroke in heart failure (HF), their findings are inconsistent and difficult to interpret because of heterogeneity in study design and population. Although HF remains a highly fatal disease, the excess mortality imparted from stroke is unknown.

METHODS

A random sample of cases of HF from 1979 to 1999 was identified and validated according to Framingham criteria. Strokes were identified by screening medical diagnoses and subsequent physician validation. Stroke risk in HF was compared with the risk in the general population with standardized morbidity ratios. Associations between selected characteristics and stroke were examined using proportional hazards regression.

RESULTS

The study cohort included 630 persons with incident HF. During a median of 4.3 years of follow-up, 102 (16%) experienced an ischemic stroke. Heart failure was associated with a 17.4-fold increased risk for stroke compared with the general population in the first 30 days after HF diagnosis and remained elevated during 5 years of follow-up. Older persons with prior stroke or diabetes were more likely to experience stroke after HF diagnosis. Persons with stroke after HF were 2.31 times more likely to die compared with persons without stroke.

CONCLUSIONS

In the community, persons with HF have a large increase in the risk for ischemic stroke compared with the general population. Stroke results in a >2-fold increase in mortality. Thus, prevention of stroke has the potential to improve survival among patients with HF, particularly among the elderly and those with diabetes or prior stroke.