Sex-specific differences in adverse outcome events among patients with atrial fibrillation.

OBJECTIVE: To assess whether women with atrial fibrillation (AF) have a higher risk of adverse events than men during long-term follow-up since controversial data have been published. METHODS: In the context of two very similar observational multicentre cohort studies, we prospectively followed 3894 patients (28% women) with previously documented AF for a median of 4.02 (3.00-5.83) years. The primary outcome was a composite of ischaemic stroke, myocardial infarction and cardiovascular death. Secondary outcomes included the individual components of the composite outcome, hospitalisation for heart failure, major and clinically relevant non-major bleeding, stroke or systemic embolism and non-cardiovascular death. RESULTS: Mean age was 73.1 years in women vs 70.8 years in men. The incidence of the primary endpoint in women versus men was 2.46 vs 3.24 per 100 patient-years, respectively (adjusted HR (aHR) 0.74, 95% CI 0.58 to 0.94; p=0.01). Women died less frequently from cardiovascular (aHR 0.57, 95% CI 0.41 to 0.78; p<0.001) and non-cardiovascular causes (aHR 0.68, 95% CI 0.47 to 0.98; p=0.04). There were no significant sex-specific differences in stroke (incidence 1.05 vs 1.00; aHR 1.02, 95% CI 0.70 to 1.49, p=0.93), myocardial infarction (incidence 0.67 vs 0.72; aHR 0.98, 95% CI 0.61 to 1.57, p=0.94), major and clinically relevant non-major bleeding (incidence 4.51 vs 4.34; aHR 0.95, 95% CI 0.79 to 1.15, p=0.63) or heart failure hospitalisation (incidence 3.28 vs 3.07; aHR 1.06, 95% CI 0.85 to 1.32, p=0.60). CONCLUSION: In this large study of patients with established AF, women had a lower risk of death than men, but there were no sex-specific differences in other adverse outcomes.

Sex differences in outcomes of primary prevention implantable cardioverter-defibrillator therapy: combined registry data from eleven European countries.

Aims: Therapy with an implantable cardioverter defibrillator (ICD) is established for the prevention of sudden cardiac death (SCD) in high risk patients. We aimed to determine the effectiveness of primary prevention ICD therapy by analysing registry data from 14 centres in 11 European countries compiled between 2002 and 2014, with emphasis on outcomes in women who have been underrepresented in all trials. Methods and results: Retrospective data of 14 local registries of primary prevention ICD implantations between 2002 and 2014 were compiled in a central database. Predefined primary outcome measures were overall mortality and first appropriate and first inappropriate shocks. A multivariable model enforcing a common hazard ratio for sex category across the centres, but allowing for centre-specific baseline hazards and centre specific effects of other covariates, was adjusted for age, the presence of ischaemic cardiomyopathy or a CRT-D, and left ventricular ejection fraction ≤25%. Of the 5033 patients, 957 (19%) were women. During a median follow-up of 33 months (IQR 16-55 months) 129 women (13%) and 807 men (20%) died (HR 0.65; 95% CI: [0.53, 0.79], P-value < 0.0001). An appropriate ICD shock occurred in 66 women (8%) and 514 men (14%; HR 0.61; 95% CI: 0.47-0.79; P = 0.0002). Conclusion: Our retrospective analysis of 14 local registries in 11 European countries demonstrates that fewer women than men undergo ICD implantation for primary prevention. After multivariate adjustment, women have a significantly lower mortality and receive fewer appropriate ICD shocks.

Autonomic nervous system activity as risk predictor in the medical emergency department: a prospective cohort study.

OBJECTIVES: To evaluate heart rate deceleration capacity, an electrocardiogram-based marker of autonomic nervous system activity, as risk predictor in a medical emergency department and to test its incremental predictive value to the modified early warning score. DESIGN: Prospective cohort study. SETTING: Medical emergency department of a large university hospital. PATIENTS: Five thousand seven hundred thirty consecutive patients of either sex in sinus rhythm, who were admitted to the medical emergency department of the University of Tübingen, Germany, between November 2010 and March 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Deceleration capacity of heart rate was calculated within the first minutes after emergency department admission. The modified early warning score was assessed from respiratory rate, heart rate, systolic blood pressure, body temperature, and level of consciousness as previously described. Primary endpoint was intrahospital mortality; secondary endpoints included transfer to the ICU as well as 30-day and 180-day mortality. One hundred forty-two patients (2.5%) reached the primary endpoint. Deceleration capacity was highly significantly lower in nonsurvivors than survivors (2.9 ± 2.1 ms vs 5.6 ± 2.9 ms; p < 0.001) and yielded an area under the receiver-operator characteristic curve of 0.780 (95% CI, 0.745-0.813). The modified early warning score model yielded an area under the receiver-operator characteristic curve of 0.706 (0.667-0.750). Implementing deceleration capacity into the modified early warning score model led to a highly significant increase of the area under the receiver-operator characteristic curve to 0.804 (0.770-0.835; p < 0.001 for difference). Deceleration capacity was also a highly significant predictor of 30-day and 180-day mortality as well as transfer to the ICU. CONCLUSIONS: Deceleration capacity is a strong and independent predictor of short-term mortality among patients admitted to a medical emergency department.

Sympathetic activity-associated periodic repolarization dynamics predict mortality following myocardial infarction.

BACKGROUND: Enhanced sympathetic activity at the ventricular myocardium can destabilize repolarization, increasing the risk of death. Sympathetic activity is known to cluster in low-frequency bursts; therefore, we hypothesized that sympathetic activity induces periodic low-frequency changes of repolarization. We developed a technique to assess the sympathetic effect on repolarization and identified periodic components in the low-frequency spectral range (≤0.1 Hz), which we termed periodic repolarization dynamics (PRD). METHODS: We investigated the physiological properties of PRD in multiple experimental studies, including a swine model of steady-state ventilation (n=7) and human studies involving fixed atrial pacing (n=10), passive head-up tilt testing (n=11), low-intensity exercise testing (n=11), and beta blockade (n=10). We tested the prognostic power of PRD in 908 survivors of acute myocardial infarction (MI). Finally, we tested the predictive values of PRD and T-wave alternans (TWA) in 2,965 patients undergoing clinically indicated exercise testing. RESULTS: PRD was not related to underlying respiratory activity (P<0.001) or heart-rate variability (P=0.002). Furthermore, PRD was enhanced by activation of the sympathetic nervous system, and pharmacological blockade of sympathetic nervous system activity suppressed PRD (P≤0.005 for both). Increased PRD was the strongest single risk predictor of 5-year total mortality (hazard ratio 4.75, 95% CI 2.94-7.66; P<0.001) after acute MI. In patients undergoing exercise testing, the predictive value of PRD was strong and complementary to that of TWA. CONCLUSION: We have described and identified low-frequency rhythmic modulations of repolarization that are associated with sympathetic activity. Increased PRD can be used as a predictor of mortality in survivors of acute MI and patients undergoing exercise testing. TRIAL REGISTRATION: ClinicalTrials.gov NCT00196274. FUNDING: This study was funded by Angewandte Klinische Forschung, University of Tübingen (252-1-0).

[Hyponatremia--should it be ignored or diagnosed?--Case 8/2011]. / Hyponatriämie--ignorieren oder diagnostizieren?--Fall 8/2011.

UNLABELLED: HISTORY, CLINICAL FINDINGS: A 72-year-old dehydrated female was admitted to our emergency department. She presented with a decreased level of consciousness and had experienced a fall. Her medication included hydrochlorothiazide and amiloride. DIAGNOSTIC: Laboratory findings showed a severe hyponatremia with a serum sodium concentration of 107 mmol/l and a reduced serum osmolality. Urine sodium and potassium excretion were > 30 mmol/l. A CT scan of the head did not show any signs of trauma. DIAGNOSIS, THERAPY AND CLINICAL COURSE: Using a diagnostic algorithm, the diagnosis of a hypotonic hypovolemic hyponatremia due to the intake of diuretics was confirmed. By intravenous infusion of physiological sodium chloride solution and cessation of diuretics, serum sodium concentration was raised gradually. Hereby, the patient`s state of consciousness completely normalized. CONCLUSIONS: Hyponatremia represents the most frequent electrolyte disturbance of hospitalized patients. It correlates with neurological deficits, proneness to falling and intrahospital mortality. Due to diagnostic insecurity of many physicians, the finding of a hyponatremia is often ignored or misclassified. Standardized approaches using diagnostic algorithms improve diagnostic accuracy. The here presented algorithm is based on only few parameters: serum and urine osmolality, urine sodium and potassium. Besides gradual raise of serum sodium, therapy of the underlying cause is essential, for example cessation of diuretics. For patients with syndrome of inadequate secretion of antidiuretic hormone (SIADH; hypotonic isovolemic hyponatremia), selective arginin-vasopressin-receptor 2-antagonists (vaptans) are a new therapeutic option. However, due to high costs, we only see an indication for patients with SIADH who are not able to consequently comply with fluid restriction.

Heart rate turbulence to guide treatment for prevention of sudden death.

Heart rate turbulence (HRT) denotes the baroreflex-mediated short-term oscillation of cardiac cycle lengths after spontaneous ventricular premature complexes. The physiological pattern of HRT consists of brief heart rate acceleration followed by more gradual heart rate deceleration before the heart rate returns to baseline. Physiological mechanisms of HRT are complex and require an intact interplay between both sympathetic and parasympathetic nervous systems. The strong and independent prognostic value of HRT in identifying postinfarction patients at high risk for death has been validated in six retrospective and three prospective studies together enrolling more than 8000 patients. This evidence qualifies HRT as a promising tool for selection of patients who might benefit from implantation of a cardioverter-defibrillator. Moreover, HRT predicts poor outcome in patients with heart failure. It is not only correlated with a patient's clinical status, but also recovers when heart failure treatment, including beta-blockers, angiotensin-converting enzyme inhibitors, or cardiac resynchronization therapy, is effective. Therefore, HRT might also be used as a treatment target to guide pharmacotherapy of heart failure.

ADP-receptor blockade: A case for personalised pharmacotherapy?

The dual antiplatelet therapy consisting of aspirin and the ADP-receptor blocker clopidogrel is the current standard medication after acute coronary events. However, clopidogrel is characterised by a high interindividual response variability, insufficient inhibition of platelet aggregation in a significant number of patients, relatively slow onset of efficacy and potential interaction with different co-medication via diverse hepatic cytochrome enzymes. In various trials, response variability of clopidogrel was translated into a higher rate of recurrent cardiovascular events. Different clinical and non-genetic factors contribute to the phenomenon of clopidogrel response variability. An individualised antithrombotic pharmacotherapy taking these factors into account, including the definition of status of response, verification of the efficacy by standardised platelet function testing, intensified or alternative platelet inhibition would be the ultimate goal for patients treated with clopidogrel. Currently, new drugs are on the way and promise a more consistent efficacy and smaller amount of response variability. However, the bleeding risk in subgroups of patients and further side effect profile remains to be clearly defined. Therefore, risk stratification models are warranted to identify patients who benefit from personalised pharmacotherapy in terms of improved clinical net benefit. In this review, we discuss treatment failure of clopidogrel based on platelet function testing, the mechanism of established and new ADP-blockers as well as new therapeutic principles.