The Relationship Between Body Mass Index and In-Hospital Mortality in Patients Following Coronary Artery Bypass Grafting Surgery.

Background: The association between Body Mass Index (BMI) and clinical outcomes following coronary artery bypass grafting (CABG) remains controversial. Our objective was to investigate the real-world relationship between BMI and in-hospital clinical course and mortality, in patients who underwent CABG. Methods: A sampled cohort of patients who underwent CABG between October 2015 and December 2016 was identified in the National Inpatient Sample (NIS) database. Outcomes of interest included in-hospital mortality, peri-procedural complications and length of stay. Patients were divided into 6 BMI (kg/m2) subgroups; (1) under-weight ≤19, (2) normal-weight 20-25, (3) over-weight 26-30, (4) obese I 31-35, (5) obese II 36-39, and (6) extremely obese ≥40. Multivariable logistic regression model was used to identify predictors of in-hospital mortality. Linear regression model was used to identify predictors of length of stay (LOS). Results: An estimated total of 48,710 hospitalizations for CABG across the U.S. were analyzed. The crude data showed a U-shaped relationship between BMI and study population outcomes with higher mortality and longer LOS in patients with BMI ≤ 19 kg/m2 and in patients with BMI ≥40 kg/m2 compared to patients with BMI 20-39 kg/m2. In the multivariable regression model, BMI subgroups of ≤19 kg/m2 and ≥40 kg/m2 were found to be independent predictors of mortality. Conclusions: A complex, U-shaped relationship between BMI and mortality was documented, confirming the "obesity paradox" in the real-world setting, in patients hospitalized for CABG.

The Relationship Between Body Mass Index and In-Hospital Mortality in the Contemporary Era of an Acute Myocardial Infarction Management.

BACKGROUND: The association between body mass index (BMI) and clinical outcomes following an acute myocardial infarction (AMI) remains controversial. Our objective was to investigate the relationship between BMI and AMI presentation, in-hospital clinical course and mortality in the contemporary era of AMI management. METHODS: Patients, hospitalized for an AMI between October 2015 and December 2016, were identified in the National Inpatient Sample (NIS) database. Socio-demographic and clinical data, including BMI, were collected and outcomes, including length of stay and mortality, were analyzed. Patients were divided into 6 BMI (kg/m2) subgroups; under-weight (≤19), normal-weight (20-25), over-weight (26-30), obese I (31-35), obese II (36-39) and extremely obese (≥40). Multivariable logistic regression model was used to identify predictors of in-hospital mortality. Linear regression model was used to identify predictors of length of stay (LOS). RESULTS: An estimated total of 125,405 hospitalizations for an AMI across the US were analyzed. Compared to the other BMI subgroups, the under-weight, normal-weight and extremely obese groups presented with a non-ST segment elevation AMI (NSTEMI) more frequently and were less likely to undergo coronary revascularization. The data show a J-shaped relationship between BMI and study outcomes with lower mortality in patients with BMI over 25 compared to normal- and low-weight patients. In the multivariate regression model, BMI group was found to be an independent predictor of mortality. CONCLUSION: J-shaped relationship between BMI and mortality was documented in patients hospitalized for an AMI in the recent years. These findings confirm that the "obesity paradox" persists during the contemporary era of an AMI management.

Sudden cardiac arrest as the initial presentation for left ventricular noncompaction cardiomyopathy.

A 37-year-old man without a significant medical history had an out-of-hospital sudden cardiac arrest. A bystander started cardiopulmonary resuscitation, and emergency medical services arrived promptly, confirmed ventricular fibrillation, and restored sinus rhythm. An emergent coronary arteriogram was normal. Transthoracic echocardiography revealed a severely reduced left ventricular ejection fraction and suggested left ventricular noncompaction. The patient's heart failure with reduced ejection fraction was treated with carvedilol, lisinopril, and spironolactone, and after he was weaned from the ventilator he received an implantable cardioverter-defibrillator. The patient's identical twin was treated in the same fashion for a sudden cardiac arrest. Although many experts think that left ventricular noncompaction cardiomyopathy is a distinct nosological entity, others think that it is simply a dilated cardiomyopathy with unusually prominent left ventricular trabeculae.

Renal Sympathetic Denervation Protects the Failing Heart Via Inhibition of Neprilysin Activity in the Kidney.

BACKGROUND: Sustained sympathetic activation contributes to the progression of myocardial cell injury, cardiac fibrosis, and left ventricular (LV) dysfunction in heart failure (HF). OBJECTIVES: This study investigated the effects of radiofrequency renal nerve denervation (RF-RDN) on the pathobiology of HF and the interaction between the renal sympathetic nerves and natriuretic peptide (NP) metabolism. METHODS: Spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) were subjected to 45 min of coronary artery ligation and reperfusion for 12 weeks. At 4 weeks post-reperfusion, SHR and WKY underwent either bilateral RF-RDN or sham-RDN. RESULTS: Following RF-RDN in both strains, LV ejection fraction remained significantly above those levels in respective sham-RDN rats, and at the end of the 12-week study, rats in both strains had significantly reduced LV fibrosis and improved vascular function. RF-RDN therapy significantly improved vascular reactivity to endothelium-dependent and -independent vasodilators as well as vascular compliance in the setting of severe HF. Improvements in LV function were accompanied by significant elevations in circulating NP as compared to those associated with sham-RDN. Further investigation into the cause of increased circulating NP levels demonstrated that RF-RDN significantly inhibited renal neprilysin activity in SHR and WKY with HF. Likewise, chronic treatment with the beta1 antagonist bisoprolol inhibited renal neprilysin activity and increased circulation NP levels in WKY with HF. CONCLUSIONS: This study identifies a novel endogenous pathway by which the renal nerves participate in the degradation of cardioprotective NP. Furthermore, removal of the influence of the renal nerves on kidney function attenuates renal neprilysin activity, augments circulating NP levels, reduces myocardial fibrosis, and improves LV function in the setting of HF.

Photoplethysmography as a single source for analysis of sleep-disordered breathing in patients with severe cardiovascular disease.

Sleep-disordered breathing and Cheyne-Stokes breathing are often not diagnosed, especially in cardiovascular patients. An automated system based on photoplethysmographic signals might provide a convenient screening and diagnostic solution for patient evaluation at home or in an ambulatory setting. We compared event detection and classification obtained by full polysomnography (the 'gold standard') and by an automated new algorithm system in 74 subjects. Each subject underwent overnight polysomnography, 60 in a hospital cardiology department and 14 while being tested for suspected sleep-disordered breathing in a sleep laboratory. The sleep-disordered breathing and Cheyne-Stokes breathing parameters measured by a new automated algorithm system correlated very well with the corresponding results obtained by full polysomnography. The sensitivity of the Cheyne-Stokes breathing detected from the system compared to full polysomnography was 92% [95% confidence interval (CI): 78.6-98.3%] and specificity 94% (95% CI: 81.3-99.3%). Comparison of the Apnea Hyponea Index with a cutoff level of 15 shows a sensitivity of 98% (95% CI: 87.1-99.6%) and specificity of 96% (95% CI: 79.8-99.3%). The detection of respiratory events showed agreement of approximately 80%. Regression and Bland-Altman plots revealed good agreement between the two methods. Relative to gold-standard polysomnography, the simply used automated system in this study yielded an acceptable analysis of sleep- and/or cardiac-related breathing disorders. Accordingly, and given the convenience and simplicity of its application, this system can be considered as a suitable platform for home and ambulatory screening and diagnosis of sleep-disordered breathing in patients with cardiovascular disease.

Long-term assessment of nocturnal Cheyne-Stokes respiration in patients with heart failure.

PURPOSE: Cheyne-Stokes respiration (CSR) is a known controversial prognostic marker in patients with heart failure (HF). Little is known, moreover, about the development and progress of CSR in such patients. The CSR progress over time may be indicative for clinical deterioration in patients with HF disease METHODS: Prospective cohort sleep studies, with algorithm-based analyses of continuously or periodically monitored changes over time using standard pulse oximeter. Home testing for 4 months of patients recruited from the cardiology department of a large community medical center in Haifa, Israel. A total of 36 patients, 31 men and five women, aged between 50 and 74 years, with symptomatic chronic HF. RESULTS: Out of the 36 patients, 15 (42%) patients were found to have CSR. The CSR cycle length was chosen as the characteristic parameter which determines the periodicity of the event and its length. Analyses of CSR cycle length and duration in the 15 patients showed changes over time in the length of the CSR event only in patient with New York Heart Association (NYHA) 4 classification. CONCLUSIONS: Nocturnal CSR in patients with HF show small variations over time in the prevalence or duration of the cycle length and could be a marker for entering stage 4 or deterioration in the NYHA class of HF patient. Moreover, it may take years for HF patients to develop CSR or to increase the length of the cycle length of existing CSR, if they develop it at all.

Application of implantable hemodynamic monitoring in the management of patients with diastolic heart failure: a subgroup analysis of the COMPASS-HF trial.

BACKGROUND: Nearly half of all patients with chronic heart failure (HF) have a normal ejection fraction (EF), and abnormal diastolic function (ie, diastolic heart failure [DHF]). However, appropriate management of DHF patients remains a difficult and uncertain challenge. METHODS AND RESULTS: The Chronicle Offers Management to Patients with Advanced Signs and Symptoms of Heart Failure (COMPASS-HF) trial was designed to evaluate whether an implantable hemodynamic monitor (IHM) was safe and effective in reducing the number of heart failure-related events (HFRE) in patients with chronic HF. The current study presents data on a prespecified and planned subgroup analysis from the COMPASS-HF trial: 70 patients with an EF > or =50% (ie, DHF). As such, this represents a subgroup analysis of the COMPASS-HF Trial. DHF patients were randomized to IHM-guided care (treatment) vs. standard care (control) for 6 months. All 70 patients received optimal medical therapy, but the hemodynamic information from the IHM was used to guide patient management only in the treatment group. The HFRE rate in DHF patients randomized to treatment was 0.58 events/6 months compared with DHF patients randomized to control, which was 0.73 events/6 months; this represented a 20% nonsignificant reduction in the overall HFRE rate in the treatment group (95% CI = -46, 56, P = .66). There was a 29% nonsignificant reduction in the relative risk of a HF hospitalization in the DHF patients randomized to treatment compared with DHF patients randomized to control (95% CI = -69, 70, P = .43). CONCLUSIONS: The IHM was shown to be safe and was associated with a very low system-related and procedure-related complication rate in DHF patients. However, in this subgroup analysis limited to 70 DHF patients, the addition IHM-guided care did not significantly lower the rate of HFR events. The results of this subgroup analysis in DHF patients, for whom there are currently no proven, effective management strategies, will be used to design future studies defining the effects of IHM-guided care in patients with DHF.

Transition from chronic compensated to acute decompensated heart failure: pathophysiological insights obtained from continuous monitoring of intracardiac pressures.

BACKGROUND: Approximately half of all patients with chronic heart failure (HF) have a decreased ejection fraction (EF) (systolic HF [SHF]); the other half have HF with a normal EF (diastolic HF [DHF]). However, the underlying pathophysiological differences between DHF and SHF patients are incompletely defined. The purpose of this study was to use echocardiographic and implantable hemodynamic monitor data to examine the pathophysiology of chronic compensated and acute decompensated HF in SHF versus DHF patients. METHODS AND RESULTS: Patients were divided into 2 subgroups: 204 had EF <50% (SHF) and 70 had EF >or=50% (DHF). DHF patients had EF of 58+/-8%, end-diastolic dimension of 50+/-10 mm, estimated resting pulmonary artery diastolic pressure (ePAD) of 16+/-9 mm Hg, and diastolic distensibility index (ratio of ePAD to end-diastolic volume) of 0.11+/-0.06 mm Hg/mL. In contrast, SHF patients had EF of 24+/-10%, end-diastolic dimension of 68+/-11 mm, ePAD of 18+/-7 mm Hg, and diastolic distensibility index of 0.06+/-0.04 mm Hg/mL (P<0.05 versus DHF for all variables except ePAD). In SHF and DHF patients who developed acute decompensated HF, these events were associated with a significant increase in ePAD, from 17+/-7 to 22+/-7 mm Hg (P<0.05) in DHF and from 21+/-9 to 24+/-8 mm Hg (P<0.05) in SHF. As a group, patients who did not have acute decompensated HF events had no significant changes in ePAD. CONCLUSIONS: Significant structural and functional differences were found between patients with SHF and those with DHF; however, elevated diastolic pressures play a pivotal role in the underlying pathophysiology of chronic compensated and acute decompensated HF in both SHF and DHF.

Randomized controlled trial of an implantable continuous hemodynamic monitor in patients with advanced heart failure: the COMPASS-HF study.

OBJECTIVES: The purpose of this study was to determine whether a heart failure (HF) management strategy using continuous intracardiac pressure monitoring could decrease HF morbidity. BACKGROUND: Patients with HF may experience frequent decompensations that require hospitalization despite intensive treatment and follow-up. METHODS: The COMPASS-HF (Chronicle Offers Management to Patients with Advanced Signs and Symptoms of Heart Failure) study was a prospective, multicenter, randomized, single-blind, parallel-controlled trial of 274 New York Heart Association functional class III or IV HF patients who received an implantable continuous hemodynamic monitor. Patients were randomized to a Chronicle (Medtronic Inc., Minneapolis, Minnesota) (n = 134) or control (n = 140) group. All patients received optimal medical therapy, but the hemodynamic information from the monitor was used to guide patient management only in the Chronicle group. Primary end points included freedom from system-related complications, freedom from pressure-sensor failure, and reduction in the rate of HF-related events (hospitalizations and emergency or urgent care visits requiring intravenous therapy). RESULTS: The 2 safety end points were met with no pressure-sensor failures and system-related complications in only 8% of the 277 patients who underwent implantation (all but 4 complications were successfully resolved). The primary efficacy end point was not met because the Chronicle group had a nonsignificant 21% lower rate of all HF-related events compared with the control group (p = 0.33). A retrospective analysis of the time to first HF hospitalization showed a 36% reduction (p = 0.03) in the relative risk of a HF-related hospitalization in the Chronicle group. CONCLUSIONS: The implantable continuous hemodynamic monitor-guided care did not significantly reduce total HF-related events compared with optimal medical management. Additional trials will be necessary to establish the clinical benefit of implantable continuous hemodynamic monitor-guided care in patients with advanced HF.

Utility of impedance cardiography for the identification of short-term risk of clinical decompensation in stable patients with chronic heart failure.

OBJECTIVES: This study sought to assess the potential utility of impedance cardiography (ICG) in predicting clinical deterioration in ambulatory patients with heart failure (HF). BACKGROUND: Impedance cardiography uses changes in thoracic electrical impedance to estimate hemodynamic variables, but its ability to predict clinical events has not been evaluated. METHODS: We prospectively evaluated 212 stable patients with HF and a recent episode of clinical decompensation who underwent serial clinical evaluation and blinded ICG testing every 2 weeks for 26 weeks and were followed up for the occurrence of death or worsening HF requiring hospitalization or emergent care. RESULTS: During the study, 59 patients experienced 104 episodes of decompensated HF (16 deaths, 78 hospitalizations, and 10 emergency visits). Multivariate analysis identified 6 clinical and ICG variables that independently predicted an event within 14 days of assessment. These included three clinical variables (visual analog score, New York Heart Association functional class, and systolic blood pressure) and three ICG parameters (velocity index, thoracic fluid content index, and left ventricular ejection time). The three ICG parameters combined into a composite score was a powerful predictor of an event during the next 14 days (p = 0.0002). Visits with a high-risk composite score had 2.5 times greater likelihood and those with a low-risk score had a 70% lower likelihood of a near-term event compared with visits at intermediate risk. CONCLUSIONS: These results suggest that when performed at regular intervals in stable patients with HF with a recent episode of clinical decompensation, ICG can identify patients at increased near-term risk of recurrent decompensation.

Mycotic pseudo-aneurysm of the ascending thoracic aorta after cardiac transplantation.

A large mycotic pseudo-aneurysm of the ascending thoracic aorta was found in a patient with empyema and infectious mediastinitis after an orthotopic heart transplant procedure. The patient underwent surgical resection of the pseudo-aneurysm with patch aortoplasty and was treated with appropriate long-term antibiotic therapy. The patient continues to do well 3 months after surgery. Early surgical intervention combined with pre-operative and prolonged post-operative antibiotic therapy and close follow-up is essential in these patients.

Peripheral vascular reactivity in patients with pulsatile vs axial flow left ventricular assist device support.

BACKGROUND: Left ventricular assist devices (LVADs) are either pulsatile or axial flow devices. The latter can be operated at a low-speed setting to allow pulsatility or at a high-speed setting to create continuous flow. The purpose of this study was to compare the effect of continuous flow and pulsatile flow on peripheral vascular reactivity. METHODS: Twenty consecutive patients were divided into two groups based on the type of LVAD they received. Ten patients had a pulsatile flow LVAD, and 10 had an axial flow LVAD. For the purpose of the study protocol, the axial flow devices were operated at a high speed to ensure continuous flow. The patients' peripheral artery vasoreactivity was assessed with an ultrasound vascular transducer that measured flow-mediated dilation (FMD). RESULTS: The FMD of the patients supported with pulsatile flow (15.6 +/- 5%) was higher than the FMD of the patients supported with temporary continuous flow (1.8 +/- 3%). The difference was statistically significant (p < 0.0001). CONCLUSIONS: Pulsatile flow is associated with a better peripheral vascular reactivity than continuous flow. Patients supported by axial flow devices should be kept on the lowest speed setting to allow maximum pulsatility.

Is native aortic valve commissural fusion in patients with long-term left ventricular assist devices associated with clinically important aortic insufficiency?

BACKGROUND: Long-term left ventricular assist device (LVAD) support diminishes flow through the native aortic valve and decreases valve motion. This may cause aortic valve commissural fusion. The clinical importance of such fusion is not well understood. METHODS: Thirty-three consecutive patients receiving long-term LVAD support were followed up until transplantation or death. In each case, the native aortic valve was examined pathologically for commissural fusion. Pathology findings were correlated with hemodynamic performance as assessed by both LVAD pump flow and echocardiography. RESULTS: Seventeen of the 33 patients had some degree of native aortic valve commissural fusion. Four patients had fusion at 2 commissures; of these, 2 had clinically significant native valve aortic insufficiency (2+ or greater), and 1 exhibited trace insufficiency of the native aortic valve. Thirteen patients had fusion at only 1 aortic commissure; of these, 2 had clinically significant aortic insufficiency (2+ or greater), and 3 had trace or mild (1+) insufficiency of native aortic valve. Two of the 4 patients with fusion at 2 commissures required increased LVAD support of >3 liters/min/cm2. No patient with fusion of only 1 commissure required increased LVAD support. Three patients with no commissural fusion of the aortic valve required increased LVAD support secondary to sepsis. CONCLUSIONS: Commissural fusion of the native aortic valve occurs in a significant number of patients receiving long-term LVAD support and can necessitate increased levels of LVAD support. Recognition of this phenomenon may allow development of strategies to minimize commissural fusion and extend LVAD pump life.

Prognostic value of the QTc interval after cardiac transplantation.

BACKGROUND: Although QTc interval prolongation is considered a risk factor for adverse outcome in the non-transplant population, its predictive value in heart transplant recipients has not been studied yet. This study was conducted to determine whether prolonged QTc interval is a useful predictor of outcome in heart transplant recipients. METHODS: QTc intervals were measured in 587 adult patients who underwent heart transplantation between May 1982 and January 2002. QT interval duration was determined by averaging 3 consecutive beats in all 12 leads of the standard electrocardiogram (ECG) and corrected with the Bazett formula. Baseline ECGs were obtained within 7 days after transplantation; follow-up ECGs were recorded annually at the time of routine angiography. Patients were followed over 85 +/- 65 months (range, 3 months-17 years). RESULTS: During follow-up, 241 patients died. The mean QTc interval duration in these patients was comparable with that in the remaining cohort (432 +/- 26 msec vs 423 +/- 25 msec, p = 0.07). However, patients with a relative increase in QTc duration of >or=10% between the first and second post-transplantation year (DeltaQTc >or= 10%) had a 6.86-times higher risk of dying compared with patients with DeltaQTc < 10% (p = 0.0005). Furthermore, DeltaQTc >or= 10% was the only independent predictor of long-term mortality on multivariate analysis (p = 0.0008). CONCLUSIONS: A relative increase in QTc interval duration of >or=10% between the first and second post-transplantation year is a strong, independent predictor of mortality in heart transplant recipients.

Left ventricular assist device therapy for end-stage congestive heart failure: from REMATCH to the future.

Therapy for patients with end-stage cardiomyopathy continues to evolve, but clearly it must now involve left ventricular assist device therapy as either bridge-to-transplantation or destination therapy. Patients who are selected for left ventricular assist device support must be able to undergo the surgical implantation procedure safely and avoid common complications such as right heart failure. Adequate patient selection is essential and can typically be accomplished using simple hemodynamic measures. As left ventricular assist device technology evolves, pulsatile devices will likely be replaced by their newer axial flow counterparts, which offer decided advantages. In the future, therapy for end-stage heart failure will involve aggressive use of mechanical assist device therapy and, as more patients are supported with these devices and the technology improves, this will become a burgeoning field for cardiologists and cardiovascular surgeons.