TpTe and TpTe/QT: novel markers to predict sudden cardiac death in ESRD? / TpTe e TpTe/QT: novos marcadores para prever morte súbita cardíaca na DRT?

ABSTRACT Introduction: Reliable markers to predict sudden cardiac death (SCD) in patients with end stage renal disease (ESRD) remain elusive, but echocardiogram (ECG) parameters may help stratify patients. Given their roles as markers for myocardial dispersion especially in high risk populations such as those with Brugada syndrome, we hypothesized that the Tpeak to Tend (TpTe) interval and TpTe/QT are independent risk factors for SCD in ESRD. Methods: Retrospective chart review was conducted on a cohort of patients with ESRD starting hemodialysis. Patients were US veterans who utilized the Veterans Affairs medical centers for health care. Average age of all participants was 66 years and the majority were males, consistent with a US veteran population. ECGs that were performed within 18 months of dialysis initiation were manually evaluated for TpTe and TpTe/QT. The primary outcomes were SCD and all-cause mortality, and these were assessed up to 5 years following dialysis initiation. Results: After exclusion criteria, 205 patients were identified, of whom 94 had a prolonged TpTe, and 61 had a prolonged TpTe/QT interval (not mutually exclusive). Overall mortality was 70.2% at 5 years and SCD was 15.2%. No significant difference was observed in the primary outcomes when examining TpTe (SCD: prolonged 16.0% vs. normal 14.4%, p=0.73; all-cause mortality: prolonged 55.3% vs. normal 47.7%, p=0.43). Likewise, no significant difference was found for TpTe/QT (SCD: prolonged 15.4% vs. normal 15.0%, p=0.51; all-cause mortality: prolonged 80.7% vs. normal 66.7%, p=0.39). Conclusions: In ESRD patients on hemodialysis, prolonged TpTe or TpTe/QT was not associated with a significant increase in SCD or all-cause mortality.

RESUMO Introdução: Marcadores confiáveis para predizer morte súbita cardíaca (MSC) em pacientes com doença renal terminal (DRT) permanecem elusivos, mas os parâmetros do ecocardiograma (ECG) podem ajudar a estratificar os pacientes. Devido a seus papéis como marcadores para a dispersão miocárdica, especialmente em populações de alto risco, como aquelas com síndrome de Brugada, nós hipotetizamos que o intervalo pico da onda T ao final da onda T (TpTe) e TpTe/QT são fatores de risco independentes para MSC na DRT. Métodos: Revisão retrospectiva do prontuário foi realizada em uma coorte de pacientes com DRT iniciando a hemodiálise. Os pacientes eram veteranos de guerra americanos que utilizavam os centros médicos do Veterans Affairs para atendimento médico. A idade média de todos os participantes foi de 66 anos e a maioria era do sexo masculino, consistente com uma população veterana dos EUA. ECGs que foram realizados dentro de 18 meses após o início da diálise, e foram avaliados manualmente para TpTe e TpTe/QT. Os desfechos primários foram MSC e mortalidade por todas as causas, e estes foram avaliados até 5 anos após o início da diálise. Resultados: Após o critério de exclusão, foram identificados 205 pacientes, dos quais 94 com TpTe prolongado e 61 com intervalo TpTe/QT prolongado (não mutuamente exclusivo). A mortalidade geral foi de 70,2% em 5 anos e a MSC foi de 15,2%. Nenhuma diferença significativa foi observada nos desfechos primários ao se avaliar o TpTe (MSC: prolongado 16,0% versus normal 14,4%, p = 0,73; mortalidade por todas as causas: prolongado 55,3% vs. normal 47,7%, p = 0,43). Da mesma forma, nenhuma diferença significativa foi encontrada para TpTe/QT (MSC: prolongado 15,4% vs. normal 15,0%, p = 0,51; mortalidade por todas as causas: prolongado 80,7% vs. normal 66,7%, p = 0,39). Conclusões: Em pacientes com insuficiência renal terminal em hemodiálise, TpTe ou TpTe/QT prolongados não foram associados a um aumento significativo da morte súbita ou mortalidade por todas as causas.

TpTe and TpTe/QT: novel markers to predict sudden cardiac death in ESRD?

INTRODUCTION: Reliable markers to predict sudden cardiac death (SCD) in patients with end stage renal disease (ESRD) remain elusive, but electrocardiogram (ECG) parameters may help stratify patients. Given their roles as markers for myocardial dispersion especially in high risk populations such as those with Brugada syndrome, we hypothesized that the Tpeak to Tend (TpTe) interval and TpTe/QT are independent risk factors for SCD in ESRD. METHODS: Retrospective chart review was conducted on a cohort of patients with ESRD starting hemodialysis. Patients were US veterans who utilized the Veterans Affairs medical centers for health care. Average age of all participants was 66 years and the majority were males, consistent with a US veteran population. ECGs that were performed within 18 months of dialysis initiation were manually evaluated for TpTe and TpTe/QT. The primary outcomes were SCD and all-cause mortality, and these were assessed up to 5 years following dialysis initiation. RESULTS: After exclusion criteria, 205 patients were identified, of whom 94 had a prolonged TpTe, and 61 had a prolonged TpTe/QT interval (not mutually exclusive). Overall mortality was 70.2% at 5 years and SCD was 15.2%. No significant difference was observed in the primary outcomes when examining TpTe (SCD: prolonged 16.0% vs. normal 14.4%, p=0.73; all-cause mortality: prolonged 55.3% vs. normal 47.7%, p=0.43). Likewise, no significant difference was found for TpTe/QT (SCD: prolonged 15.4% vs. normal 15.0%, p=0.51; all-cause mortality: prolonged 80.7% vs. normal 66.7%, p=0.39). CONCLUSIONS: In ESRD patients on hemodialysis, prolonged TpTe or TpTe/QT was not associated with a significant increase in SCD or all-cause mortality.

Antianginal Agents for the Management of Stable Ischemic Heart Disease: A Review.

Antianginal medications are an important aspect of optimal medical therapy for the management of angina in patients with stable ischemic heart disease. The lack of a standardized definition of effective antianginal therapy and the lack of clear understanding of the underlying evidence have often been cited as reasons for the large variations in the use of these particular classes of pharmacologic agents in contemporary clinical practice. Hence, we performed a search of the PubMed database and identified published manuscripts examining the effect of common antianginal agents on improving anginal parameters and on important clinical outcomes such as mortality, myocardial infarction, and repeat revascularization from multiple large randomized, controlled trials, systematic reviews, meta-analyses, and outcomes data from observational studies in patients with stable ischemic heart disease. The most commonly used antianginal agents (beta-blockers, nitrates, calcium channel blockers, and ranolazine) demonstrated equivalent efficacy in improving patient reported ischemic symptoms and quantitative exercise parameters. With regards to mortality, beta-blockers are beneficial in the setting of depressed left ventricular systolic function. In contrast, recent evidence points toward the lack of similar benefit of beta-blockers in patients with preserved systolic function, even in the setting of prior myocardial infarction. No survival benefit has been identified with the use of calcium channel blockers, nitrates, or ranolazine. Currently, guidance regarding objective measurement and up titration of antianginal therapy is missing. There is an unmet need for development of potentially novel and clinically relevant methodology to assess the intensity and/or efficacy of antianginal therapy.

Relation between achieved heart rate and outcomes in patients with atrial fibrillation (from the Atrial Fibrillation Follow-up Investigation of Rhythm Management [AFFIRM] Study).

Many patients with atrial fibrillation (AF) are treated with rate control and anticoagulation. However, the relation between the degree of heart rate (HR) control and clinical outcome is uncertain. We assessed whether lower achieved HR at rest and/or lower achieved exercise HR was associated with improved prognosis, quality of life (QoL), and functional status among patients in the AFFIRM study. Patients in the rate control arm and who were in AF at baseline and 2 months were included. Patients were grouped by quartile of achieved HR at rest (44 to 69, 70 to 78, 79 to 87, 88 to 148 beats/min) and achieved exercise HR following a 6-minute walk (53 to 82, 83 to 92, 93 to 106, 107 to 220 beats/min). QoL measurements and functional status were also analyzed. Complete data were available for 680 patients for achieved HR at rest, 349 patients for achieved exercise HR, and 118 patients for QoL. Survival free from cardiac hospitalization and overall survival were not significantly different among quartiles of achieved HR at rest (p = 0.19 and p = 0.8, respectively) or achieved exercise HR (p = 0.77 and p = 0.14, respectively). After controlling for covariates, there remained no significant relation between either achieved HR at rest or achieved exercise HR and event-free survival (hazard ratio 0.95, p = 0.35 and hazard ratio 0.98, p = 0.81) or overall survival (hazard ratio 1.03, p = 0.70 and hazard ratio 1.22, p = 0.13). Furthermore, there was no significant association between achieved HR and QoL measurements, New York Heart Association functional class, or 6-minute walking distance. After 2 months of drug titration, neither achieved HR at rest nor achieved exercise HR predicted survival free from cardiovascular hospitalization, overall survival, QoL, or functional status among patients with AF.