Beta-blocker is Effective in Reducing Cardiovascular Events in Patients with Chronic Heart Failure Complicated by Atrial Fibrillation

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• 作者：Nobuyuki Shiba ; Tomohiro Tada ; Tsuyoshi Shinozaki ; Koji Fukuda ; Jun Takahashi ; Jun Watanabe
• 关键词：Noninvasive cardiac monitoring ; Bioimpedance ; Heart failure outcomes ; Tissue perfusion
• 刊名：Journal of Cardiac Failure
• 出版年：2005
• 出版时间：December 2005
• 年：2005
• 卷：11
• 期：9, Supplement 1
• 页码：S294
• 全文大小：16 K

文摘

The evaluation of heart failure is routinely based on subjective patient symptoms and physician examination. We propose the noninvasive evaluation of microvascular and global perfusion can objectify heart failure severity and provide additional prognostic information.

Methods

A prospective, observational pilot study of patients previously stratified into New York Heart Association (NYHA) heart failure classes and who after a routine cardiology clinic evaluation were felt to be at their stable baseline state. Measurements included: thoracic impedance (Z_o), hypothenar tissue hemoglobin oxygen saturation (S_tO₂), and Z_o-derived cardiac index (CI). To determine if adverse outcomes (hospitalization or death) occurred, patients or their families were contacted 6 months after enrollment and their charts reviewed. Monitor values between the NYHA classes were compared using analysis of variance. Values of those who later developed adverse outcomes were compared to patients who remained stable using a Student t-test (P < .05 considered significant). A Kaplan-Meier survival curve was used to describe the adverse outcome rate over time, and a Cox's proportional hazards model was used to relate perfusion values to adverse outcomes.

Results

There were no differences in CI (P = .08), Z_o (P = .38), or S_tO₂ (P = .14) found between NYHA classes (n = 46). After 6 months, 6 patients required hospitalization for heart failure and 1 died. This group had lower S_tO₂ values compared with the stable group (P = .015). The time course of the adverse events was found not to be due to chance alone when evaluated using a Kaplan-Meier curve and the S_tO₂ was significantly associated with time to adverse outcome (P < .05).

Conclusions

Outpatient heart failure patients who later develop adverse outcomes have significantly lower S_tO₂ values than those who remain stable. This suggests cardiac performance in stable heart failure patients may be better reflected at the microvascular level using measures such as S_tO₂ as opposed to a global level using the physical exam or impedance cardiography. S_tO₂ may serve as a predictor for future adverse events and as an adjunct to current evaluation techniques.