Predictors of Improvement in Exercise Capacity After Cardiac Rehabilitation Differ Between Octogenarian and Young-Old Patients With Acute Myocardial Infarction.

BACKGROUND: Whether the magnitude and predictors of improvement in exercise capacity after cardiac rehabilitation (CR) are the same between young-old (YO) and octogenarian (OCT) patients with acute myocardial infarction (AMI) is unknown.Methods and Results: We studied 284 YO (age range 65-69 years; mean [±SD] 67±1 years) and 65 OCT (age range ≥80 years; mean [±SD] 83±2 years) patients who participated in a post-AMI CR program. After 3 months of CR, peak oxygen uptake (PV̇O2) measured during cardiopulmonary exercise testing improved significantly in both age groups (P<0.01), although the percentage increase in PV̇O2(%∆PV̇O2) was significantly smaller in the OCT than YO group (5.4±13.7% vs. 10.0±12.8%; P<0.01). Multiple regression analysis demonstrated that independent predictors of %∆PV̇O2were the number of outpatient CR (OPCR) sessions attended (P=0.015), left ventricular ejection fraction (P=0.028), and baseline PV̇O2(P=0.0007) in the YO group; and the number of sessions attended (P=0.018), atrial fibrillation (P=0.042), and the presence of nutritional risk (Geriatric Nutritional Risk Index ≤98; P=0.036) in the OCT group. CONCLUSIONS: The predictors of improvement in exercise capacity after CR differed between the YO and OCT patients with AMI. To obtain a greater improvement in PV̇O2in CR, frequent OPCR session attendance may be necessary in both groups; in addition, particularly in OCT patients, better nutritional status may be important.

Exercise-Based Cardiac Rehabilitation Improves Exercise Capacity Regardless of the Response to Cardiac Resynchronization Therapy in Patients With Heart Failure and Reduced Ejection Fraction.

BACKGROUND: In patients with chronic heart failure with reduced ejection fraction (HFrEF), cardiac resynchronization therapy (CRT) improves left ventricular ejection fraction (LVEF) and exercise-based cardiac rehabilitation (ECR) enhances exercise capacity. This study examined the relationship between the 2 responses.Methods and Results:Sixty-four consecutive HFrEF patients who participated in a 3-month ECR program after CRT were investigated. Patients were categorized according to a median improvement in peak oxygen uptake (PV̇O2) after ECR of 7% as either good (n=32; mean percentage change in PV̇O2[%∆PV̇O2]=23.2%) or poor (n=32; mean %∆PV̇O2=2.5%) responders. There was no significant difference in baseline characteristics between the good and poor responders, except for PV̇O2(51% vs. 59%, respectively; P=0.01). The proportion of good CRT responders was similar between the good and poor responders (%∆LVEF ≥10%; 53% vs. 47%, respectively; P=NS). Overall, there was no significant correlation between %∆LVEF after CRT and %∆PV̇O2after ECR. Notably, among poor CRT responders (n=32), the prevalence of atrial fibrillation (0% vs. 29%; P<0.03) and baseline PV̇O2(48% vs. 57%; P<0.05) were significantly lower among those with a good (n=15) than poor (n=17) response to ECR. CONCLUSIONS: In patients with HFrEF, good ECR and CRT responses are unrelated. A good PV̇O2response to ECR can be achieved even in poor CRT responders, particularly in those with a sinus rhythm or low baseline PV̇O2.

Active Participation in Outpatient Cardiac Rehabilitation Is Associated With Better Prognosis After Coronary Artery Bypass Graft Surgery　- J-REHAB CABG Study.

BACKGROUND: There is little evidence regarding the effect of outpatient cardiac rehabilitation (CR) on exercise capacity or the long-term prognosis in patients after coronary artery bypass graft surgery (CABG). This study aimed to determine whether participation in outpatient CR improves exercise capacity and long-term prognosis in post-CABG Japanese patients in a multicenter cohort.Methods and Results:We enrolled 346 post-CABG patients who underwent cardiopulmonary exercise testing during early (2-3 weeks) and late (3-6 months) time points after surgery. They formed the Active (n=240) and Non-Active (n=106) CR participation groups and were followed for 3.5 years. Primary endpoint was a major adverse cardiac event (MACE): all-cause death or rehospitalization for acute myocardial infarction/unstable angina/worsening heart failure. Peak oxygen uptake at 3-5 months from baseline was significantly more increased in Active than in Non-Active patients (+26±24% vs. +19±20%, respectively; P<0.05), and the MACE rate was significantly lower in Active than Non-Active patients (3.4% vs. 10.5%, respectively; P=0.02). Multivariate Cox proportional hazard analysis showed that participation in outpatient CR was a significant prognostic determinant of MACE (P=0.03). CONCLUSIONS: This unique study showed that a multicenter cohort of patients who underwent CABG and actively participated in outpatient CR exhibited greater improvement in exercise capacity and better survival without cardiovascular events than their counterparts who did not participate.

Cardiac Mechanoenergetics in Patients with Acute Myocardial Infarction: From Pressure-Volume Loop Diagram Related to Cardiac Oxygen Consumption.

Acute myocardial infarction (AMI) results in significant changes in cardiac structure and functions, leading to left ventricular remodeling and subsequent systolic and diastolic dysfunction. To improve current approaches in diagnoses, treatments, and prevention of cardiovascular diseases, a better understanding of cardiac mechanoenergetics, including systolic performance and energy demand, becomes paramount. In this review, we summarize cardiac mechanics, cardiac energetics, and their relationship in complications related to AMI using 2 important physiologic frameworks, pressure-volume loops and the Vo2-pressure-volume area relationship diagram, as they are powerful tools for understanding physiologic behavior and mechanoenergetics of the left ventricle.

Efficacy of Cardiac Rehabilitation in Heart Failure Patients With Low Body Mass Index.

BACKGROUND: Low body mass index (BMI) is a relevant prognostic factor for heart failure (HF), but HF patients with low BMI are reported to be at risk of not receiving optimal drug treatment. We sought to evaluate the efficacy of cardiac rehabilitation (CR) in patients with low vs. normal BMI. Methods and Results: We studied 152 consecutive patients (low BMI, n=32; normal BMI, n=119) who participated in a 3-month CR program. Low BMI was defined as <18.5 kg/m2and normal BMI, as 18.5≤BMI<25 kg/m2. All patients underwent cardiopulmonary exercise testing and muscle strength testing at the beginning and end of the 3-month CR program. After CR, a significantly greater proportion of HF patients with low BMI had a positive change in peak V̇O2than in the normal BMI group (91% vs. 70%; P=0.010). Average percent change in peak V̇O2was significantly greater in patients with low vs. normal BMI (17.1±2.8% vs. 7.8±1.5%; P<0.001). In addition, on multivariable logistic regression, low BMI was an independent predictor of a positive change in peak V̇O2after CR (OR, 3.97; 95% CI: 1.10-14.31; P=0.035). CONCLUSIONS: CR has a greater effect in patients with low than normal BMI, and low BMI is an independent predictor of a positive change in peak V̇O2. Thus, CR should be strongly recommended for HF patients with low BMI.

Combination of Peak Exercise Systolic Blood Pressure and Left Atrial Diameter as a Novel Non-Spirometry Prognostic Predictor Comparable to Peak Oxygen Uptake for Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Although peak oxygen uptake (pV̇O2) is a well-established powerful prognostic predictor in heart failure (HF) patients, implementation of cardiopulmonary exercise testing (CPX) is limited by its complex analysis. We aimed to develop a new bivariate predictor obtained without respiratory gas measurement, comparable to pV̇O2.Methods and Results:We studied 560 consecutive HF patients with ejection fraction (EF) <45% who underwent CPX. During a median follow-up of 49.0 months, the composite of all-cause death or HF hospitalization occurred in 228 patients (40.7%) and all-cause death in 111 (19.8%). pV̇O2was the strongest single predictor of the composite outcome (chi-square, 99.3). Among the bivariate non-spirometry parameters, the ratio of systolic blood pressure at peak exercise to left atrial diameter (pSBP/LAD) was the strongest predictor (chi-square, 112.4). Patients with pSBP/LAD <2.8 mmHg/mm, compared with those with pSBP/LAD ≥2.8 mmHg/mm, had a hazard ratio of 3.84 (95% confidence interval, 2.95-5.04) for the composite outcome and 3.66 (2.50-5.37) for all-cause death. In the subgroup with pV̇O2<14 mL/kg/min (n=149), where pV̇O2had no further predictive value, pSBP was the strongest single predictor, and the predictive power of pSBP/LAD was more enhanced. CONCLUSIONS: pSBP/LAD was a new powerful predictor of HF hospitalization and death, comparable to pV̇O2, in HF with reduced EF. Because of its simplicity and high availability, this index has the potential for more widespread use than pV̇O2.

Anticoagulation combined with antiplatelet therapy in patients with left ventricular thrombus after first acute myocardial infarction.

Aims: There are limited data about the optimal anti-thrombotic therapy for preventing embolism while minimizing bleeding events in patients with first acute myocardial infarction (AMI) complicated by left ventricular thrombus (LVT). Methods and results: Among 2301 consecutive patients with AMI hospitalized between 2001 and 2014, we studied 1850 patients with first AMI who discharged alive to investigate clinical characteristics, incidence of systemic embolism (SE), and association between anticoagulation and embolic or bleeding events. Left ventricular thrombus was diagnosed by echocardiography, left ventriculography, or cardiac magnetic resonance imaging in 92 (5.0%) patients (62 ± 12 years). During a median follow-up period of 5.4 years (interquartile range 2.1-9.1 years), SE occurred in 15 of 92 patients with LVT (16.3%) and 51 of 1758 patients without LVT (2.9%), respectively. Kaplan-Meier analysis showed a significantly higher incidence of SE in the LVT group (log-rank test, P < 0.001). Multivariate analysis showed that LVT was an independent predictor of SE. Among the LVT patients treated with vitamin K antagonists (n = 84), we compared the patients with therapeutic range (TTR) ≥50% (n = 34) and those with TTR <50% (n = 50). Only one embolic event developed in the TTR ≥50% group and nine embolic events developed in the TTR <50% group (2.9% vs. 19%, P = 0.036). There was no difference in major bleeding events (TTR ≥50%; 9% vs. TTR <50%; 8%, P = 0.89). Conclusion: Appropriate anticoagulation therapy may decrease the incidence of embolic events without increasing the incidence of bleeding events in patients with first AMI complicated by LV thrombus.

Coronary Artery Ectasia Predicts Future Cardiac Events in Patients With Acute Myocardial Infarction.

OBJECTIVE: Coronary artery ectasia (CAE) is an infrequently observed vascular phenotype characterized by abnormal vessel dilatation and disturbed coronary flow, which potentially promote thrombogenicity and inflammatory reactions. However, whether or not CAE influences cardiovascular outcomes remains unknown. APPROACH AND RESULTS: We investigated major adverse cardiac events (MACE; defined as cardiac death and nonfatal myocardial infarction [MI]) in 1698 patients with acute MI. The occurrence of MACE was compared in patients with and without CAE. CAE was identified in 3.0% of study subjects. During the 49-month observation period, CAE was associated with 3.25-, 2.71-, and 4.92-fold greater likelihoods of experiencing MACE (95% confidence interval [CI], 1.88-5.66; P<0.001), cardiac death (95% CI, 1.37-5.37; P=0.004), and nonfatal MI (95% CI, 2.20-11.0; P<0.001), respectively. These cardiac risks of CAE were consistently observed in a multivariate Cox proportional hazards model (MACE: hazard ratio, 4.94; 95% CI, 2.36-10.4; P<0.001) and in a propensity score-matched cohort (MACE: hazard ratio, 8.98; 95% CI, 1.14-71.0; P=0.03). Despite having a higher risk of CAE-related cardiac events, patients with CAE receiving anticoagulation therapy who achieved an optimal percent time in target therapeutic range, defined as ≥60%, did not experience the occurrence of MACE (P=0.03 versus patients with percent time in target therapeutic range <60% or without anticoagulation therapy). CONCLUSIONS: The presence of CAE predicted future cardiac events in patients with acute MI. Our findings suggest that acute MI patients with CAE are a high-risk subset who might benefit from a pharmacological approach to controlling the coagulation cascade.

Predictors of improvements in exercise capacity during cardiac rehabilitation in the recovery phase after coronary artery bypass graft surgery versus acute myocardial infarction.

This study aimed to elucidate the predictors of improvements in exercise capacity during cardiac rehabilitation (CR) in the recovery phase after coronary artery bypass graft surgery (CABG) versus acute myocardial infarction (AMI). We studied 152 patients (91 after AMI and 61 after CABG) who participated in a 3-month CR program. All patients underwent a cardiopulmonary exercise test, blood tests, maximal quadriceps isometric strength (QIS) measurement, and bioelectrical impedance body composition measurement at the beginning and end of the 3-month CR program. At baseline, the percentage of predicted peak oxygen uptake (%pred-PVO2), maximal QIS, and hemoglobin (Hb) were significantly lower, while C-reactive protein (CRP) was significantly higher, in the CABG than the AMI group. After the 3-month CR, %change in PVO2 (%ΔPVO2) was significantly greater in the CABG than the AMI group (18 ± 15% vs 11 ± 12%, P < 0.01). At univariate analysis, baseline plasma brain natriuretic peptide (BNP), %change in maximal QIS after CR (%Δ maximal QIS), and change in plasma hemoglobin (ΔHb) significantly correlated with %ΔPVO2 in the CABG group, whereas only baseline %pred-PVO2 did so in the AMI group. Multiple regression analysis revealed that the same factors were independent and significant predictors of %ΔPVO2 in the CABG and AMI groups. The predictors of improvements in exercise capacity after CR differed between patients after CABG or AMI. Specifically, in CABG patients both enhancing QIS and correcting anemia may contribute to greater improvements in exercise capacity after CR, while a more effective CR program should be designed for CABG patients with high baseline BNP.

Prognostic impact of chronic total coronary occlusion on long-term outcomes in implantable cardioverter-defibrillator recipients with ischaemic heart disease.

AIMS: The prognostic impact of chronic total coronary occlusion (CTO) on implantable cardioverter-defibrillator (ICD) recipients remains unclear. METHODS AND RESULTS: Eighty-four consecutive patients with ischaemic heart disease who received ICD therapy for primary or secondary prevention were analysed. We investigated all-cause mortality and major adverse cardiac events (MACEs) including cardiac death, appropriate device therapy, hospitalization for heart failure, and ventricular assist device implantation. Of the study patients (mean age 70 ± 8 years; 86% men), 34 (40%) had CTO. There were no significant differences in age, left ventricular ejection fraction (LVEF), New York Heart Association functional class III or IV status, and proportion who underwent secondary prevention between patients with CTO (CTO group) and without CTO (non-CTO group). During a median follow-up of 3.8 years (interquartile range 2.7-5.4 years), the CTO group tended to have a higher MACE rate (log-rank P = 0.054) than the non-CTO group. Within the CTO group, there was no difference in the MACE rate between patients with and without viable myocardium. In patients with ICD for secondary prevention (n = 47), 16 patients (34%) with CTO had a higher MACE rate than patients without CTO (log-rank P < 0.01). Cox proportional hazards regression analysis showed that the presence of CTO, but not LVEF, was associated with a higher MACE rate. Multivariate analysis showed that the presence of CTO was a predictor of MACE (P < 0.05). CONCLUSION: In patients with ischaemic heart disease receiving ICD implantation, the presence of CTO has an adverse impact on long-term prognosis, especially as secondary prevention.

Improvement in Exercise Capacity by Exercise Training Associated With Favorable Clinical Outcomes in Advanced Heart Failure With High B-Type Natriuretic Peptide Level.

BACKGROUND: The efficacy of exercise training (ET) programs and its relationship with long-term clinical outcomes in advanced heart failure (HF) patients with high levels of B-type natriuretic peptide (BNP) remain uncertain.Methods and Results:We studied 340 consecutive HF patients with ejection fraction (EF) <45% who completed a 3-month ET program. Patients with BNP ≥200 pg/mL (High-BNP, n=170) had more advanced HF characteristics, including lower EF (25.0±8.6% vs. 28.1±8.0%, P=0.0008), than those with BNP <200 pg/mL. In the High-BNP patients, peak oxygen uptake (V̇O2) was significantly increased by 8.3±16.2% during the ET program, and changes in peak V̇O2inversely correlated with changes in BNP (R=-0.453, P<0.0001) and changes in ventilatory efficiency (V̇E/V̇CO2slope) (R=-0.439, P<0.0001). During a median follow-up of 46 months, patients in the upper tertile of changes in peak V̇O2(≥13.0%), compared with those in the lower tertile (<1.0%), had lower rates of the composite of all-cause death or HF hospitalization (37.9% vs. 54.4%, P=0.036) and all-cause death (8.6% vs. 24.6%, P=0.056). In the multivariate analysis, change in peak V̇O2was a significant independent predictor of the composite outcome and all-cause death. CONCLUSIONS: Even among advanced HF patients with high BNP level, an ET program significantly improved exercise capacity, and a greater improvement in exercise capacity was associated with greater decreases in BNP level and V̇E/V̇CO2slope and more favorable long-term clinical outcomes.

Impact of decreased serum albumin levels on acute kidney injury in patients with acute decompensated heart failure: a potential association of atrial natriuretic peptide.

Although hypoalbuminemia at admission is a risk for acute kidney injury (AKI) and mortality in patients with acute decompensated heart failure (ADHF), the clinical significance of decreased serum albumin levels (DAL) during ADHF therapy has not been elucidated. This study aimed to evaluate whether DAL was associated with AKI, and whether intravenous atrial natriuretic peptide (ANP) administration, which provides an effective treatment for ADHF but promotes albumin extravasation, was associated with DAL and AKI. A total of 231 consecutive patients with ADHF were enrolled. AKI was defined as ≥0.3 mg/dl absolute or 1.5-fold increase in serum creatinine levels within 48 h. AKI occurred in 73 (32%) of the 231 patients during ADHF therapy. The median value of decreases in serum albumin levels was 0.3 g/dl at 7 days after admission. When DAL was defined as ≥0.3 g/dl decrease in serum albumin levels, DAL occurred in 113 patients, and was independently associated with AKI. Of the 231 patients, 73 (32%) were treated with intravenous ANP. DAL occurred more frequently in patients receiving ANP than in those not receiving ANP (77 vs. 36%, p < 0.001), and ANP was independently associated with DAL. The incidence of AKI was higher in patients receiving ANP than in those not receiving ANP (48 vs. 24%, p < 0.001). ANP was independently associated with AKI. In conclusion, DAL is associated with AKI. Intravenous ANP administration may be one of the promoting factors of DAL, which leads to AKI, indicating a possible novel mechanism of AKI.

Prevalence, Clinical Features, and Prognosis of Acute Myocardial Infarction Attributable to Coronary Artery Embolism.

BACKGROUND: Coronary artery embolism (CE) is recognized as an important nonatherosclerotic cause of acute myocardial infarction. Its prevalence, clinical features, and prognosis remain insufficiently characterized. METHODS AND RESULTS: We screened 1776 consecutive patients who presented with de novo acute myocardial infarction between 2001 and 2013. CE was diagnosed based on criteria encompassing histological, angiographic, and other diagnostic imaging findings. The prevalence, clinical characteristics, treatment strategies, in-hospital outcomes, and long-term risk of CE recurrence or major adverse cardiac and cerebrovascular events (cardiac death, fatal arrhythmia, or recurrent thromboembolism) were evaluated. The prevalence of CE was 2.9% (n=52), including 8 (15%) patients with multivessel CE. Atrial fibrillation was the most common cause (n=38, 73%). Only 39% of patients with CE were treated with vitamin K antagonists, and the median international normalized ratio was 1.42 (range, 0.95-1.80). Eighteen of the 30 CE patients with nonvalvular atrial fibrillation had a CHADS2 score of 0 or 1. When those patients were reevaluated using CHA2DS2-VASc, 61% were reassigned to a higher risk category. During a median follow-up of 49 months, CE and thromboembolism recurred in 5 atrial fibrillation patients. The 5-year rate of major adverse cardiac and cerebrovascular events was 27.1%. In the propensity score-matched cohorts (n=45 each), Kaplan-Meier analysis showed a significantly higher incidence of cardiac death in the CE group than in the non-CE group (hazard ratio, 9.29; 95% confidence interval, 1.13-76.5; P<0.001). CONCLUSIONS: Atrial fibrillation is the most frequent cause of CE. Patients with CE represent a high-risk subgroup of patients with acute myocardial infarction and require close follow-up.

Time to Reperfusion in ST-Segment Elevation Myocardial Infarction Patients With vs. Without Pre-Hospital Mobile Telemedicine 12-Lead Electrocardiogram Transmission.

BACKGROUND: Prehospital ECG improves survival following ST-segment elevation myocardial infarction (STEMI). Although a new International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations placed new emphasis on the role of prehospital ECG, this technology is not widely used in Japan. We developed a mobile telemedicine system (MTS) that continuously transmits real-time 12-lead ECG from ambulances in a prehospital setting. This study was designed to compare reperfusion delay between STEMI patients with different prehospital transfer pathways. METHODS AND RESULTS: Between 2008 and 2012, 393 consecutive STEMI patients were transferred by ambulance to hospital (PCI-capable center); 301 patients who underwent primary percutaneous coronary intervention (PCI) were enrolled prospectively. We compared time to reperfusion between patients transferred to PCI-capable hospital using the MTS (MTS group, n=37), patients directly transferred from the field to PCI-capable hospital without the MTS (field transfer group, n=125) and patients referred from a PCI-incapable hospital (interhospital transfer group, n=139). Times to reperfusion in the MTS group were significantly shorter than in the other groups, yielding substantial benefits in patients who arrived at a PCI-capable hospital within 6 h after symptom onset. On multivariate analysis, MTS use was an independent predictor of <90-min door-to-device interval (OR, 4.61; P=0.005). CONCLUSIONS: Reperfusion delay was shorter in patients using MTS than in patients without it. (Circ J 2016; 80: 1624-1633).

Regional Clinical Alliance Path and Cardiac Rehabilitation After Hospital Discharge for Acute Myocardial Infarction Patients in Japan　- A Nationwide Survey.

BACKGROUND: The regional clinical alliance path (RCAP) after discharge from an acute-phase hospital is emerging as a tool for bridging acute-phase treatment and chronic-phase disease management. However, the optimal application of RCAP for acute myocardial infarction (AMI) remains unknown in Japan, and therefore a nationwide survey of hospitals was conducted. METHODS AND RESULTS: In 2009, questionnaires were sent to 1,240 cardiology training hospitals authorized by the Japanese Circulation Society. The response rate was 62.9% (780/1,240). Of the 780 responding hospitals, 708 treated AMI, and in these hospitals the number of AMI patients and percutaneous coronary intervention (PCI) procedures performed were, respectively, 59±52 and 200±206 per year. The implementation rate of emergency PCI was high (91%), but that of outpatient cardiac rehabilitation (OPCR) was very low (18%). The implementation rate of RCAP after AMI was significantly lower (10%) than after stroke (57%). Cardiac rehabilitation (CR) was adopted as part of RCAP in only 19% (13/70) of currently operating RCAP programs. CONCLUSIONS: This first Japanese nationwide survey of RCAP after AMI showed that in contrast to the broad dissemination of acute-phase invasive treatment for AMI, there was infrequent implementation of OPCR, RCAP after AMI, and RCAP including CR. It will be necessary to broaden the use of RCAP after AMI, including OPCR. (Circ J 2016; 80: 1750-1755).

Impact of onset time of acute kidney injury on outcomes in patients with acute decompensated heart failure.

Since acute kidney injury (AKI) is not always related to mortality in patients with acute decompensated heart failure (ADHF), the aim of this study was to focus on onset time of AKI and its clinical importance. A total of 371 ADHF patients were included. The impact of AKI (≥ 0.3 mg/dl or 1.5-fold increase in serum creatinine level within 48 h) with early onset (≤ 4 days from admission) or late onset (≥ 5 days from admission) was assessed. AKI occurred in 99 patients, who were divided into two groups according to the median onset time of AKI: 50 with early onset of AKI and 49 with late onset of AKI. The maximum increase in serum creatinine level from admission was greater in patients with late onset of AKI than in patients with early onset of AKI (p = 0.012). Patients with late onset of AKI had a higher 12-month mortality rate than that in patients with early onset of AKI (log-rank test, p = 0.014). Late onset of AKI was an independent predictor of mortality (hazard ratio: 3.39, 95 % confidence interval: 1.84-6.18, p < 0.001). Late onset of AKI was associated with high blood urea nitrogen level at admission and intravenous administration of dobutamine. In conclusion, late onset of AKI related to high blood urea nitrogen level and intravenous administration of dobutamine, but not early onset of AKI, is linked to high mortality rate. Onset time of AKI may be useful for risk stratification of mortality in ADHF patients developing AKI.

Application of three-dimensional speckle tracking echocardiography to assess left ventricular regional work using wall tension-regional area loop.

Three-dimensional (3-D) speckle tracking echocardiography allows us to track a change in regional endocardial surface area. The change of regional area during a cardiac cycle should be useful for assessing left ventricular regional work. We investigated the feasibility of assessing regional work, calculated as the area within the wall tension-regional area (T-A) loop using 3-D echocardiography. Three-dimensional full-volume images were acquired using 3-D echocardiography (Artida, Toshiba) at baseline and during brief occlusion of the left circumflex coronary artery in eight dogs. Wall tension was calculated according to Laplace's law for a spherical model. Area change ratio (in %) determined by area tracking was transformed into a change of regional area (in cm(2)) by a custom software. We calculated the area within the T-A loop (TAA) in the area under transient ischemia (risk area) and the remote area as regional work and validated the T-A loop method by comparing the global integral of TAA with the total work assessed by the pressure-volume loop. During coronary occlusion, regional work for the risk area significantly decreased (baseline vs. occlusion, 26.8 ± 10.7 vs. 18.4 ± 7.8 mmHg·cm(3); P < 0.05), whereas that for the remote area did not change. The global integral of TAA closely correlated with the total work assessed by the pressure-volume loop (r = 0.91, P < 0.0001). The wall T-A loop reflected regional dysfunction caused by myocardial ischemia. This analysis using 3-D speckle tracking echocardiography might be useful to quantify left ventricular regional work.

Risk Stratification of Acute Kidney Injury Using the Blood Urea Nitrogen/Creatinine Ratio in Patients With Acute Decompensated Heart Failure.

BACKGROUND: Risk stratification of acute kidney injury (AKI) is important for acute decompensated heart failure (ADHF). The aim of this study was to determine whether clinical markers, such as the blood urea nitrogen/creatinine ratio (BUN/Cr) or BUN or creatinine values alone, stratify the risk of AKI for mortality. METHODS AND RESULTS: In all, 371 consecutive ADHF patients were enrolled in the study. AKI was defined as serum creatinine ≥0.3 mg/dl or a 1.5-fold increase in serum creatinine levels within 48 h. During ADHF therapy, AKI occurred in 99 patients; 55 patients died during the 12-month follow-up period. Grouping patients according to AKI and a median BUN/Cr at admission of 22.1 (non-AKI+low BUN/Cr, non-AKI+high BUN/Cr, AKI+low BUN/Cr, and AKI+high BUN/Cr groups) revealed higher mortality in the AKI+high BUN/Cr group (log-rank test, P<0.001). Cox's proportional hazard analysis revealed an association between AKI+high BUN/Cr and mortality, whereas the association with AKI+low BUN/Cr did not reach statistical significance. When patients were grouped according to AKI and median BUN or creatinine values at admission, AKI was associated with mortality, regardless of BUN or creatinine. CONCLUSIONS: The combination of AKI and elevated BUN/Cr, but not BUN or creatinine individually, is linked with an increased risk of mortality in ADHF patients, suggesting that the BUN/Cr is useful for risk stratification of AKI.

Targeting of high peak respiratory exchange ratio is safe and enhances the prognostic power of peak oxygen uptake for heart failure patients.

BACKGROUND: Peak oxygen uptake (V̇O2) and ventilatory efficiency (V̇E/V̇CO2slope) measured on cardiopulmonary exercise testing (CPX) are prognostic indicators in heart failure (HF) patients, but peak V̇O2is influenced by patient effort. In CPX targeting a peak respiratory exchange ratio (pRER; an objective index of effort adequacy) higher than the commonly recommended level, we assessed the safety and prognostic value of CPX parameters compared with non-CPX parameters. METHODS AND RESULTS: We studied 283 consecutive HF patients with left ventricular ejection fraction (LVEF) ≤45% (mean, 26.3%) who underwent CPX targeting pRER >1.20. The attained pRER (mean, 1.26) was consistently high irrespective of LVEF, and there was no major exercise-related adverse event. The composite of all-cause death or HF hospitalization occurred in 111 patients (39%) during a median follow-up of 47 months. Among well-known prognostic markers, peak V̇O2was the most powerful predictor of outcome as both a continuous and an optimal dichotomous variable, followed by V̇E/V̇CO2slope. On multivariate analysis, peak V̇O2was a significant independent predictor, whereas V̇E/V̇CO2slope, B-type natriuretic peptide, and LVEF were not. CONCLUSIONS: In CPX targeting pRER >1.20 for HF patients, peak V̇O2is the most powerful among well-known predictors, without an increased risk of exercise-related events. These findings advocate a high target pRER in CPX even in advanced HF.

Impact of cardiac rehabilitation on renal function in patients with and without chronic kidney disease after acute myocardial infarction.

BACKGROUND: Although there is a general fear that exercise training might deteriorate renal function in chronic kidney disease (CKD) patients, the effect of cardiac rehabilitation (CR) on renal function in acute myocardial infarction (AMI) patients with CKD remains unknown. We sought to determine whether CR is associated with amelioration or deterioration of renal function in such patients. METHODS AND RESULTS: We enrolled 528 AMI patients who participated in a 3-month CR program. Clinical data before and after CR were compared according to participation in CR and comorbidities. In patients without CKD (estimated glomerular filtration rate [eGFR] ≥60ml·min(-1)·1.73m(-2), n=348), peak oxygen uptake (VO2) and B-type natriuretic peptide (BNP) improved without a change in eGFR. In contrast, in patients with CKD (eGFR <60ml·min(-1)·1.73m(-2), n=180), eGFR improved (48±12 to 53±15ml·min(-1)·1.73m(-2), P<0.001), together with improvements in peak VO2 and BNP. When patients with CKD were divided into non-active (≤1time/week, n=70) and active participants (≥1.1time/week, n=110) according to attendance in CR, active participants showed an improvement in eGFR (50±10 to 53±13ml·min(-1)·1.73m(-2), P<0.001), whereas eGFR did not change in non-active participants. Similar results were obtained in each subgroup of patients with hypertension, dyslipidemia, or diabetes mellitus. CONCLUSIONS: In AMI patients with CKD, active participation in CR was associated with improved peak VO2, BNP, and eGFR.