Nobuaki Hamazaki

Quadriceps Strength as a Predictor of Mortality in Coronary Artery Disease

BACKGROUND The purpose of this study was to investigate the prognostic value of quadriceps isometric strength (QIS) in coronary artery disease (CAD). METHODS The study population consisted of 1314 patients aged >30 years (64.7 ± 10.6 years, 1051 male) with CAD who were hospitalized for acute coronary syndrome or coronary artery bypass grafting. Maximal QIS was evaluated as a marker of leg strength and expressed relative to body weight (% body weight). The primary and secondary endpoints were all-cause death and cardiovascular (CV) death, respectively. RESULTS During a mean follow-up of 5.0 ± 3.5 years, corresponding to 6537 person-years, there were 118 all-cause deaths and 63 CV deaths. A higher QIS remained associated with decreased all-cause mortality and CV mortality risks (hazard ratio for increasing 10% body weight of QIS 0.77, 95% confidence interval 0.67-0.89, P < .001 for all-cause death; hazard ratio 0.66, 95% confidence interval 0.54-0.82, P < .001 for CV death) after adjustment for other prognostic factors. The inclusion of QIS significantly increased both continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) for all-cause death (cNRI: 0.25, P = .009; IDI: 0.007, P = .030) and CV death (cNRI: 0.34, P = .008; IDI: 0.013, P = .008). CONCLUSIONS A high level of quadriceps strength was strongly associated with a lower risk of both all-cause and CV mortality in patients with CAD. Evaluation of QIS offered incremental prognostic information beyond pre-existing risk factors.

Complementary Role of Arm Circumference to Body Mass Index in Risk Stratification in Heart Failure.

OBJECTIVES This study was performed to investigate the complementary role of arm circumference to body mass index (BMI) in risk stratification of patients with heart failure (HF). BACKGROUND High BMI is associated with improved survival in patients with HF. However, it does not discriminate between fat and lean muscle as a predominant factor. METHODS BMI, waist circumference (WC), and mid-upper arm circumference (MUAC) were evaluated in 570 consecutive Japanese patients with HF (mean age 67.4 ± 14.0 years). Patients were stratified into low and high groups according to BMI, WC, and MUAC and combined into low- or high-BMI and low- or high-WC groups or low- or high-BMI and low- or high-MUAC groups. The endpoint was all-cause mortality. RESULTS Seventy deaths occurred over a median follow-up period of 1.5 years (interquartile range: 0.7 to 2.8 years). After adjusting for several pre-existing prognostic factors, including Seattle Heart Failure Score and exercise capacity, BMI (hazard ratio [HR]: 0.68; p = 0.016), WC (HR: 0.76; p = 0.044), and MUAC (HR: 0.52; p < 0.001) were all inversely associated with prognosis. Compared with the high-BMI/high-WC group, both the low-BMI/high-WC and low-BMI/low-WC groups showed comparably poorer prognosis. However, the low-BMI/low-MUAC group but not the low-BMI/high-MUAC group showed poorer prognosis than the high-BMI/high-MUAC group. Adding MUAC to BMI (0.70 vs. 0.63, p = 0.012) but not WC to BMI (0.64 vs. 0.63, p = 0.763) significantly increased the area under the curve on receiver-operating characteristic curve analysis. CONCLUSIONS MUAC, but not WC, plays a complementary role to BMI in predicting prognosis in patients with HF.

Safety of neuromuscular electrical stimulation in patients implanted with cardioverter defibrillators.

Neuromuscular electrical stimulation (NMES) is one of the few exercise modes that have been confirmed to be effective for advanced heart failure patients. Previous clinical trials that verified the effects of NMES excluded patients with implantable cardioverter defibrillators (ICDs). We investigated whether NMES to leg muscles could be applied in heart failure patients implanted with ICDs. As a result, we found that NMES could be conducted without any instances of electromagnetic interference. NMES to leg muscles could be applied safely to ICD patients if the aforementioned common stimulation methods were used with sufficient monitoring during NMES.

Gait speed has comparable prognostic capability to six-minute walk distance in older patients with cardiovascular disease

Background Although gait speed and six-minute walk distance are used to assess functional capacity in older patients with cardiovascular disease, their prognostic capabilities have not been directly compared. Methods The study population was identified from the Kitasato University Cardiac Rehabilitation Database and consisted of 1474 patients ≥60 years old with a mean age of 72.2 ± 7.1 years that underwent evaluation of both usual gait speed and six-minute walk distance in routine geriatric assessment between 1 June 2008–30 September 2015. Both gait speed and six-minute walk distance were determined on the same day at hospital discharge. Results Mean gait speed and six-minute walk distance in the whole population were 1.04 m/s and 381 m, respectively, and were strongly positively correlated (r = 0.80, p < 0.001). A total of 180 deaths occurred during a follow-up of 2.3 ± 1.9 years. After adjusting for confounding factors, both gait speed (adjusted hazard ratio per 0.1 m/s increase: 0.87, 95% confidence interval: 0.81–0.93, p < 0.001) and six-minute walk distance (adjusted hazard ratio per 10-metre increase: 0.96, 95% confidence interval: 0.94–0.97, p < 0.001) were independent predictors of all-cause mortality. There was no significant difference in prognostic capability between gait speed and six-minute walk distance (c-index: 0.64 (95% confidence interval: 0.60–0.69) and 0.66 (95% confidence interval: 0.61–0.70), respectively, p = 0.357). Conclusions Gait speed and six-minute walk distance showed similar prognostic predictive ability for all-cause mortality in older cardiovascular disease patients, indicating the potential utility of gait speed as a simple risk stratification tool in older cardiovascular disease patients.

Muscle Weakness Is Associated With an Increase of Left Ventricular Mass Through Excessive Blood Pressure Elevation During Exercise in Patients With Hypertension

Autonomic imbalance in hypertension induces excessive blood pressure (BP) elevation during exercise, thereby increasing left ventricular mass (LVM). Although muscle weakness enhances autonomic imbalance by stimulating muscle sympathetic activity during exercise, it is unclear whether muscle weakness is associated with an increase of LVM in patients with hypertension. This study aimed to investigate the relationships between muscle weakness, BP elevation during exercise, and LVM in these patients. Eighty-six hypertensive patients aged 69 ± 8 years with controlled resting BP (ie, < 140/90 mmHg) were recruited. Plasma brain natriuretic peptide (BNP), left ventricular mass index (LVMI), and knee extension muscle strength were measured. Changes in plasma noradrenaline (NORA) and brachial-ankle pulse wave velocity (ba-PWV) were assessed before and after an ergometer exercise test performed at moderate intensity (ΔNORA and ΔPWV, respectively). A difference between baseline and peak systolic BP during the exercise test was defined as BP elevation during exercise (ΔSBP). Relationships between muscle strength, ΔNORA, ΔPWV, ΔSBP, BNP, and LVMI were analyzed, and significant factors increasing LVM were identified using univariate and multivariate regression analyses. Muscle strength was negatively correlated with ΔNORA (r = -0.202, P = 0.048), ΔPWV (r = -0.328, P = 0.002), ΔSBP (r = -0.230, P = 0.033), BNP (r = -0.265, P = 0.014), and LVMI (r = -0.233, P = 0.031). LVMI was positively correlated with ΔPWV (r = 0.246, P = 0.023) and ΔSBP (r = 0.307, P = 0.004). Muscle strength was a significant independent factor associated with LVMI (β = -0.331, P = 0.010). Our findings suggest that muscle weakness is associated with an increase of LVM through excessive BP elevation during exercise in patients with hypertension.

Low ankle brachial index is associated with the magnitude of impaired walking endurance in patients with heart failure

BACKGROUND Measurement of the ankle brachial index (ABI) is a simple, noninvasive means of diagnosing peripheral arterial disease, and has been shown to be associated with mortality rate. Here, we examined the association between ABI and physical function in patients with heart failure (HF). METHODS The study population consisted of 524 admitted patients (67.2±13.9years, 343 males) with HF. Blood pressure and the ABI were determined by oscillometry. Prior to hospital discharge, ABI, 6-minute walking distance, walking velocity, handgrip strength, quadriceps isometric strength, and standing balance were determined. The 524 patients were divided according to ABI as follows: ABI≤0.90 (low ABI), ABI 0.91 to 0.99 (borderline ABI), and ABI 1.00 to 1.40 (normal ABI). RESULTS Lower ABI values were associated with shorter 6-minute walking distance (p trend=0.001), slower walking velocity (p trend=0.023), and poorer standing balance (p trend=0.048). There were no significant associations between ABI and handgrip strength or quadriceps isometric strength. After adjusting for potential confounders, patients with ABI≤0.90 had shorter 6-minute walking distance compared to those with ABI 1.00 to 1.40 (adjusted mean value: 344m vs. 395m, respectively, p<0.001). There were no significant differences in any of the other physical function parameters examined. CONCLUSIONS In patients with HF, low ABI is associated with the magnitude of impairment in walking endurance.

Incremental Value of Objective Frailty Assessment to Predict Mortality in Elderly Patients Hospitalized for Heart Failure

BACKGROUND The impact of frailty on long-term prognosis in patients with heart failure (HF) remains unclear, and there is no simple and objective assessment for it. This study was performed to examine the association between frailty score and clinical outcome in elderly patients hospitalized for HF. METHODS AND RESULTS A retrospective cohort study was performed with 603 elderly patients with HF (mean age 75 ± 6 years, 378 [62.7%] men). Frailty was measured by a composite of 4 markers combined into a frailty score (possible range 0-12): gait speed, handgrip strength, serum albumin, and activities of daily living status. The patient population was divided into 2 groups with frailty score <5 (non-frail) or ≥5 (frail). The end point was all-cause mortality. Over a mean follow-up period of 1.7 ± 0.5 years, 89 patients died. After adjustment for several preexisting factors associated with prognosis, the frailty score (hazard ratio [HR] 1.11; P = .014) and frailty (HR 1.75; P = .036) were independently associated with all-cause mortality. The inclusion of frailty score significantly increased both continuous net reclassification improvement (0.341; P = .002) and integrated discrimination improvement (0.016; P = .039) for all-cause mortality. CONCLUSIONS A simple and objective frailty score was associated with health outcome in elderly patients hospitalized for HF.

Pupillary light reflex as a new prognostic marker in patients with heart failure

BACKGROUND Autonomic function can be evaluated based on the pupillary light reflex (PLR). However, the relationship between PLR and prognosis in patients with heart failure (HF) remains unclear. This study was performed to examine whether PLR could be used as a prognostic indicator in patients with HF. METHODS AND RESULTS A retrospective review was performed in 535 consecutive Japanese patients hospitalized for acute HF (mean age 66.1 ± 13.7 y). PLR was recorded at least 7 days after hospitalization for HF with the use of a pupilometer. Fifty-three patients died over a median follow-up period of 1.3 years (interquartile range 0.6-2.3 y). After adjustment for several preexisting prognostic factors, including Seattle Heart Failure Score (SHFS), PLR as assessed by recovery time (time to 63% redilation) was independently associated with all-cause mortality (hazard ratio 0.50, 95% confidence interval 0.35-0.73; P < .001). The addition of recovery time to SHFS resulted in a significant increase in the area under the curve on receiver-operating characteristic curve analysis (0.69 vs 0.77; P < .001). CONCLUSIONS PLR assessed by recovery time was an independent predictor of mortality and added prognostic information to the SHFS in patients with HF. Our results suggest that PLR may be useful as a new prognostic marker in HF patients.

SARC-F questionnaire identifies physical limitations and predicts post discharge outcomes in elderly patients with cardiovascular disease

A simple and inexpensive sarcopenia screening tool would be beneficial in clinical practice. This study was performed to determine whether SARC‐F questionnaire can be used to identify physical limitations and poor prognosis in elderly cardiovascular disease (CVD) patients.

Sarcopenia: prevalence and prognostic implications in elderly patients with cardiovascular disease

Sarcopenia has recently been given an ICD‐10 code. However, there have been no systematic investigations regarding the prevalence or prognostic value of sarcopenia in cardiovascular disease (CVD) according to the international consensus definition. The present study was performed to investigate the prevalence and prognostic value of sarcopenia in elderly patients with CVD.