Heart Rate Variability Applications in Strength and Conditioning: A Narrative Review.

Heart rate variability (HRV) is defined as the fluctuation of time intervals between adjacent heartbeats and is commonly used as a surrogate measure of autonomic function. HRV has become an increasingly measured variable by wearable technology for use in fitness and sport applications. However, with its increased use, a gap has arisen between the research and the application of this technology in strength and conditioning. The goal of this narrative literature review is to discuss current evidence and propose preliminary guidelines regarding the application of HRV in strength and conditioning. A literature review was conducted searching for HRV and strength and conditioning, aiming to focus on studies with time-domain measurements. Studies suggest that HRV is a helpful metric to assess training status, adaptability, and recovery after a training program. Although reduced HRV may be a sign of overreaching and/or overtraining syndrome, it may not be a sensitive marker in aerobic-trained athletes and therefore has different utilities for different athletic populations. There is likely utility to HRV-guided programming compared to predefined programming in several types of training. Evidence-based preliminary guidelines for the application of HRV in strength and conditioning are discussed. This is an evolving area of research, and more data are needed to evaluate the best practices for applying HRV in strength and conditioning.

The impact of the OPTN policy change on patients with a durable left ventricular assist device and chronic kidney disease: Analysis of the UNOS database.

BACKGROUND: The Organ Procurement and Transplantation Network (OPTN) implemented modifications in 2018 to the adult heart transplant allocation system to better stratify the most medically urgent transplant candidates. We evaluated the impact of these changes on patients supported by a durable left ventricular assist device (LVAD) with chronic kidney disease (CKD). OBJECTIVE: To evaluate the impact of the OPTN policy change on patients supported by durable left ventricular assist devices (LVAD) with chronic kidney disease (CKD). METHODS: We performed an analysis of patients from the United Network of Organ Sharing Database supported by durable LVAD listed for a heart transplant (HT) between October 17, 2016 and September 30, 2021. Patients were divided into two groups: pre- and postpolicy, depending on whether they were listed on or prior to October 17, 2018. Patients who were on dialysis prior to surgery or discharge were excluded from the analysis. Patients with simultaneous heart and kidney transplants were excluded. Patients who were listed for transplant prepolicy change but transplanted postpolicy change were excluded. This cohort was then subdivided into degrees of CKD based on estimated glomerular filtration rate (eGFR), which resulted in 678 patients (23.7%) in Stage 1 (GFR ≥89.499) (Prepolicy: 345, Postpolicy: 333), 1233 (43.1%) in Stage 2 (89.499 > GFR ≥ 59.499) (Prepolicy: 618, Postpolicy: 615), 613 (21.4%) in Stage 3a (59.499 > GFR ≥ 44.499) (Prepolicy: 291, Postpolicy: 322), 294 (10.3%) in Stage 3b (44.499 > GFR ≥ 29.499) (Prepolicy: 143, Postpolicy: 151), 36 (1.3%) in Stage 4 (29.499 > GFR ≥ 15) (Prepolicy: 21, Postpolicy: 15), and 9 (0.3%) in Stage 5 (15 > GFR) (Prepolicy: 4, Postpolicy: 5). The primary outcome was 1-year and 2-year post-HT survival. RESULTS: There were 2863 patients who met the study criteria (1422 prepolicy, 1441 postpolicy). Overall survival, regardless of CKD stage, was lower following the policy change (p < 0.01). There was a similar risk of primary graft failure (PGF) in the pre- and postpolicy period (1.8% vs. 1.2%, p = 0.26). 1-year overall survival was 93% (91, 94) and 89% (87, 91) in the pre- and postpolicy periods, respectively. 2-year overall survival was 89% (88, 91) and 85% (82, 87) in the pre- and postpolicy periods, respectively. For CKD Stages 1, 2, 3a, 3b, 4, and 5, 1 -year survival was 93% (91, 95), 92% (90,93), 89% (86, 91), 89% (86, 93), 80% (68, 94), and 100% (100, 100), respectively. For CKD Stages 1, 2, 3a, 3b, 4, and 5, 2-year survival was 91% (88, 93), 88% (86, 90), 84% (81, 88), 84% (80, 89), 73% (59, 90), and 100% (100, 100), respectively. Patients with CKD 1 and 2 had better survival compared to those with CKD 3 (p < 0.01) and CKD 4 and 5 (p = 0.03) in the pre- and postpolicy periods. Patients with CKD 3 did not have a survival advantage over those with CKD 4 and 5 (p = 0.25). On cox regression analysis, advancing degrees of CKD were associated with an increased risk of mortality. CONCLUSIONS: Patients with LVAD support had decreased overall survival after the OPTN policy change. Patients with more advanced CKD had lower survival than patients without advanced CKD, though they were not impacted by the OPTN policy change.

Relationship Between Obesity and Youth Athletes' Physical Activity and Exercise-Related Cardiac Symptoms.

Background: While studies have identified the negative cardiovascular effects of obesity, the effects of obesity on youth athletes are less studied. This study investigates the associations between obesity in youth athletes and exercise activity and exertional cardiac symptoms. Methods: The HeartBytes National Youth Database produced by Simon's Heart, a nonprofit that organizes adolescents' sports pre-participation examinations (PPEs), was used. This database contains demographic data, exercise-related symptoms, and electrocardiogram data obtained during PPEs. BMI was converted to percentiles, with obesity defined as BMI ≥95th percentile. Outcomes were evaluated using a chi-squared test with odds ratios (ORs) and 95% confidence intervals (CIs). Results: Of 7363 patients, there were 634 individuals with obesity. Youth athletes within normal weight ranges (5th-85th percentile) had higher exercise rates than those with underweight, overweight, or obesity (p < 0.001 for each). Athletes with obesity had higher odds of exertional symptoms overall (OR: 1.63 [CI: 1.36-1.96]; p < 0.001). However, for athletes who exercised >10 hours a week, there was no association between obesity and exertional symptoms. Athletes with obesity had higher odds of elevated blood pressure (OR: 5.35 [CI: 2.00-14.30]; p < 0.001) and hypercholesterolemia (OR: 3.84 [CI: 2.51-5.86]; p < 0.001). Conclusions: In this dataset, obesity in youth athletes is associated with decreased physical activity and increased exertional symptoms in general. Obesity is not associated with exertional symptoms in athletes who participated in higher weekly physical activity. Further studies are needed to elucidate the cause-effect relationship of these findings.

A multicenter evaluation of the HeartMate 3 risk score.

BACKGROUND: The Heartmate 3 (HM3) risk score (HM3RS) was derived and validated internally from within the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) trial population and provides 1- and 2-year mortality risk prediction for patients in those before HM3 left ventricular assist device (LVAD) implantation. We aimed to evaluate the HM3RS in nontrial unselected patients, including those not meeting inclusion criteria for MOMENTUM 3 trial enrollment. METHODS: Patients who underwent HM3 LVAD implant at 1 of 7 US centers between 2017 and 2021, with at least 1-year follow-up, were included in this analysis. Patients were retrospectively assessed for their eligibility for the MOMENTUM 3 trial based on study inclusion and exclusion criteria. HM3RS risk discrimination was evaluated using time-dependent receiver operating characteristic curve analysis for 1-year mortality for all patients and further stratified by MOMENTUM 3 trial eligibility. Kaplan-Meier curves were constructed using the HM3RS-based risk categories. RESULTS: Of 521 patients included in the analysis, 266 (51.1%) would have met enrollment criteria for MOMENTUM 3. The 1- and 2-year survival for the total cohort was 85% and 81%, respectively. There was no statistically significant difference in survival between those who met and did not meet enrollment criteria at 1 (87% vs 83%; p = 0.21) and 2 years postimplant (80% vs 78%; p = 0.39). For the total cohort, HM3RS predicted 1-year survival with an area under the curve (AUC) of 0.63 (95% confidence interval [CI]: 0.57-0.69, p < 0.001). HM3RS performed better in the subset of patients meeting enrollment criteria: AUC 0.69 (95% CI:0.61-0.77, p < 0.001) compared to the subset that did not: AUC 0.58 (95% CI: 0.49-0.66, p = 0.078). CONCLUSIONS: In this real-world evidence, multicenter cohort, 1- and 2-year survival after commercial HM3 LVAD implant was excellent, regardless of trial eligibility. The HM3RS provided adequate risk discrimination in "trial-like" patients, but predictive value was reduced in patients who did not meet trial criteria.

Late Right Heart Failure After Left Ventricular Assist Device Implantation: Contemporary Insights and Future Perspectives.

Late right heart failure (RHF) is increasingly recognized in patients with long-term left ventricular assist device (LVAD) support and is associated with decreased survival and increased incidence of adverse events such as gastrointestinal bleeding and stroke. Progression of right ventricular (RV) dysfunction to clinical syndrome of late RHF in patients supported with LVAD is dependent on the severity of pre-existing RV dysfunction, persistent or worsening left- or right-sided valvular heart disease, pulmonary hypertension, inadequate or excessive left ventricular unloading, and/or progression of the underlying cardiac disease. RHF likely represents a continuum of risk with early presentation and progression to late RHF. However, de novo RHF develops in a subset of patients leading to increased diuretic requirement, arrhythmias, renal and hepatic dysfunction, and heart failure hospitalizations. The distinction between isolated late RHF and RHF due to left-sided contributions is lacking in registry studies and should be the focus of future registry data collection. Potential management strategies include optimization of RV preload and afterload, neurohormonal blockade, LVAD speed optimization, and treatment of concomitant valvular disease. In this review, the authors discuss definition, pathophysiology, prevention, and management of late RHF.

Adverse outcomes of atrial fibrillation ablation in heart failure patients with and without cardiac amyloidosis: a Nationwide Readmissions Database analysis (2015-2019).

Aims: Atrial fibrillation (AF) in patients with cardiac amyloidosis (CA) has been linked with a worse prognosis. The current study aimed to determine the outcomes of AF catheter ablation in patients with CA. Methods and results: The Nationwide Readmissions Database (2015-2019) was used to identify patients with AF and concomitant heart failure. Among these, patients who underwent catheter ablation were classified into two groups, patients with and without CA. The adjusted odds ratio (aOR) of index admission and 30-day readmission outcomes was calculated using a propensity score matching (PSM) analysis. A total of 148 134 patients with AF undergoing catheter ablation were identified on crude analysis. Using PSM analysis, 616 patients (293 CA-AF, 323 non-CA-AF) were selected based on a balanced distribution of baseline comorbidities. At index admission, AF ablation in patients with CA was associated with significantly higher adjusted odds of net adverse clinical events (NACE) [adjusted odds ratio (aOR) 4.21, 95% CI 1.7-5.20], in-hospital mortality (aOR 9.03, 95% CI 1.12-72.70), and pericardial effusion (aOR 3.30, 95% CI 1.57-6.93) compared with non-CA-AF. There was no significant difference in the odds of stroke, cardiac tamponade, and major bleeding between the two groups. At 30-day readmission, the incidence of NACE and mortality remained high in patients undergoing AF ablation in CA. Conclusion: Compared with non-CA, AF ablation in CA patients is associated with relatively higher in-hospital all-cause mortality and net adverse events both at index admission and up to 30-day follow-up.

Trends and Predictors of Poor Outcomes in Patients With Right Heart Failure: Insights From the National Readmission Database.

Right heart failure (RHF) is a complex clinical syndrome that confers high risk of morbidity and mortality. We sought to study RHF using large national database. The study is a retrospective analysis of the National Readmission Database (NRD) of years 2017-2019. Admissions with a primary diagnosis of RHF were included. Study outcomes were temporal trends of RHF diagnosis and predictors of in-hospital mortality and 30-day readmission. Subgroup analysis according to co-presence of reduced or preserved left ventricular ejection fraction (LVEF). Multivariate logistic regression was utilized to detect predictors of poor outcome and difference between subgroups. A total of 127,503 admissions were identified from the database of which 4,717 primary RHF admissions were included in our cohort. There was a trend of increasing RHF diagnosis from 2017 4th Quarter to 2019 4th Quarter. Age, liver disease and reduced LVEF were amongst predictors of in-hospital mortality while iron deficiency anemia and a Charlson Comorbidity Score ≥ 3 were predictors of 30-day readmission. The study of real-world data contributes to a better understanding of RHF outcomes. Further studies are needed to investigate the association between RHF and different types of heart failure and its implications on clinical practice.

A systematic review, meta-analysis, and meta regression of the sham controlled renal denervation randomized controlled trials.

Renal denervation (RD) has been investigated as a novel blood pressure (BP) lowering treatment for hypertension. The primary objective of this meta-analysis was to assess the efficacy of RD and factors that may associate with treatment effect heterogeneity. The primary outcomes were raw mean differences (RMD) in 24-hour ambulatory, daytime ambulatory, nighttime, and office systolic BP (SBP) and diastolic BP (DBP) between sham control and RD. A prespecified subgroup analysis was performed comparing studies with follow-up less than versus greater than 4 months. If inter-study heterogeneity was found for any of the above outcomes, additional analyses were performed to assess potential moderator variables. Ten sham-controlled randomized trials were identified and included 1,544 participants, followed for a mean of 4.20 months. RD was associated with a statistically significant reduction in all SBP and DBP measures except for nighttime SBP (-2.64 mmHg; 95% confidence interval (CI) -5.84 to 0.56, p = 0.11) and nighttime DBP (- 1.21 mmHg; 95% CI -3.17 to 0.75, p = 0.23). Mild to moderate inter-study heterogeneity was identified for three outcomes (office SBP and nighttime SBP and DBP). Studies that followed patients for longer than 4 months had numerically lower reductions in most BP outcomes; however, there were no statistically significant interactions between subgroups. Compared to a sham procedure, RD was associated with statistically significant reductions in most measures of SBP and DBP that were within bounds of what would be expected from standard blood pressure lowering medications.

National Trends of Structural Heart Disease Interventions from 2016 to 2020 in the United States and the Associated Impact of COVID-19 Pandemic.

The Coronavirus Disease-2019 (COVID-19) pandemic placed an enormous strain on the healthcare system. Data on the impact of COVID-19 on the utilization and outcomes of structural heart disease interventions in the United States are scarce. The National Inpatient Sample from 2016 to 2020 was queried to identify adult admissions for transcatheter aortic valve replacement (TAVR), left atrial appendage occlusion (LAAO), and transcatheter end-to-end repair (TEER). The primary outcome was temporal trends of procedure utilization rate per 100,000 admissions over quarters from 2016 to 2020. The secondary outcomes were adjusted rates of in-hospital mortality, major complications, and length of stay (LOS). Among 434,630 weighted admissions (TAVR: 305,550; LAAO: 89,300; TEER: 40,160), 95,010 admissions (22%) were during the COVID-19 era. There was a decline during the second quarter of 2020 followed by an increase to the pre pandemic levels (TAVR: 220 to 253, LAAO: 57 to 109, and TEER: 31 to 36 per 100,000 admissions, Ptrend<0.001). There were no differences in the mortality or major complication rates. Median LOS has decreased in TAVR (4 days-1 day) and in TEER (3 days-1 day) but remained stable in LAAO (1 day). This nationwide analysis showed that structural heart disease interventions decreased during the early waves of COVID-19 pandemic. There was a significant reduction in hospital LOS without differences in in-hospital mortality or complication rates during the pandemic. These data suggest that hospitals adapted to the unprecedent challenges during the pandemic to provide advanced cardiac care to patients.

Temporal Trends and Sex Differences in Patients With Cardiac Amyloidosis and Heart Failure With Preserved Ejection Fraction: Retrospective Analysis of 22,015 Admissions From the National Inpatient Sample.

Cardiac amyloidosis (CA) often goes unrecognized as a cause of heart failure with preserved ejection fraction (HFpEF). There is paucity of contemporary data evaluating the trends of CA diagnosis and associated sex differences. Adult heart failure hospitalizations were identified from the National Inpatient Sample between 2016 and 2019. Hospitalizations with heart failure other than HFpEF were excluded. Hospitalizations with a diagnosis of CA were identified. A Linear regression was utilized to calculate the trend of CA diagnosis over time. A multivariate logistic regressions analysis was performed to analyze sex differences. There was an increasing trend of CA from 1.2 to 2.3 per 1000 HFpEF admission in the first quarter of 2016 to the fourth quarter of 2019 (Ptrend <0.001). In females, as compared to males, there was an increased risk of AIS (6% vs 3%, aOR: 1.68[1.24-2.27], P=0.001) and major bleeding events (10% vs 5%, aOR: 1.97[1.53-2.52], P<0.001). No difference was observed in the in-hospital mortality outcome (8% vs 7%, aOR: 1.2[0.95-1.53], P=0.12) between both groups. Our real-world contemporary analysis showed an increase in CA diagnosis from 2016 to 2019. Despite similar in-hospital mortality, females were associated with higher AIS and major bleeding events rates. Further prospective studies are needed to validate these results.

Cardiogenic Shock Due to Atrial Arrhythmia as the Initial Presentation of Transthyretin Cardiac Amyloidosis.

Atrial arrhythmias are common in transthyretin cardiac amyloidosis (ATTR-CA), with a prevalence of ≤80%. They are often not well tolerated. We describe 3 patients with decompensated heart failure and cardiogenic shock precipitated by atrial arrhythmias who ultimately received diagnoses of ATTR-CA. (Level of Difficulty: Intermediate.).

Recurrent giant cell myocarditis after heart transplant: a case report.

Background: Giant cell myocarditis (GCM) is a rare but well-known cause of fulminant myocarditis. Despite optimal medical therapy, many patients progress to orthotopic heart transplant (OHT). We present a case of recurrent GCM following OHT, including complex considerations in patient management and infectious sequelae. Case summary: A 33-year-old previously healthy male presented with 2 months of worsening shortness of breath. Transthoracic echocardiogram (TTE) demonstrated a left ventricular ejection fraction of 30-35%. After ruling out an ischaemic aetiology, he was discharged on guideline-directed medical therapy and later presented with productive cough, worsening dyspnoea on exertion, and diarrhoea. He was found to have elevated troponins and N-terminal pro-brain natriuretic peptide, lactic acidosis, progression of severe bi-ventricular dysfunction on TTE and right heart catheterization, and low cardiac index (1.0 L/min/m2) requiring inotropes. He then required left ventricular assist device as a bridge to OHT. Pathology of the apical core diagnosed GCM as the cause of his fulminant heart failure. He eventually underwent heart transplantation, which was complicated by recurrent GCM. Treatment required intensification of his immunosuppressive regimen, which led to multiple infectious sequelae including norovirus, Shiga-like toxin producing Escherichia coli, and disseminated nocardia of the lung and brain. As of the most recent follow-up, the patient is currently clinically stable. Discussion: Although recurrent GCM after OHT has been reported in the literature, the prognosis is not well understood and there are no clear guidelines regarding management. This case summarizes clinical considerations, treatment strategies, and adverse effects of recurrent GCM treatment.

Impact of ventricular arrhythmia on LVAD implantation admission outcomes.

INTRODUCTION: Ventricular arrhythmias (VAs) are common after left ventricular assist device (LVAD) implantation though data are mixed on whether these events have an impact on mortality. METHODS: The National Inpatient Sample (NIS) database from 2002-2019 was queried for LVAD implantation admissions. Secondary ICD codes were analyzed to assess for the occurrence of VAs during this admission. Propensity score matching (PSM) was used to control for confounding variables between those with versus without VAs. RESULTS: The NIS database from 2002-2019 contained 43 936 admissions with LVAD implantation. VAs occurred in 19 985 (45.4%) patients. After PSM, the study cohort consisted of 39 989 patients, 19 985 (50.0%) of which had a secondary diagnosis of VA during the admission. When compared to those without VA, those with VA were at no higher risk for in-hospital mortality (adjusted odds ratio 1.011, 99.9% CI 0.956-1.069, p = 0.699). Those with a VA were at higher risk for cardiogenic shock and requiring mechanical ventilation, tracheostomy, and percutaneous endoscopic gastrostomy placement. Patients with a VA were also at lower risk for device thrombosis. Conversely, the VA group was at no higher risk for stroke. In comparing trends from 2002 to 2019, the incidence of VAs has increased, while the mortality rate of those with and without VAs has decreased during this same period. CONCLUSION: In this retrospective study of the NIS database, VAs were common (45.4%) during the LVAD implantation admission. However, the occurrence of VAs during the implantation admission did not alter in-hospital mortality. More longitudinal studies are required to assess the long-term impact of VAs on mortality. In comparing trends from 2002-2019, the incidence of VAs has increased, while the mortality rate of those with and without VAs has decreased.

Risk Factors for Sudden Death in Athletes, Is There a Role for Screening?

Purpose of Review: Sudden cardiac death (SCD) in a young athlete is an infrequent yet devastating event often associated with substantial media attention. Screening athletes for conditions associated with SCD is a controversial topic with debate surrounding virtually each component including the ideal subject, method, and performer/interpreter of such screens. In fact, major medical societies such as the American College of Cardiology/American Heart Association and the European Society of Cardiology have discrepant recommendations on the matter, and major sporting associations have enacted a wide range of screening policies, highlighting the confusion on this subject. This review seeks to summarize the literature in this area to address the complex and disputed subject of screening young athletes for SCD. Recent Findings: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause myocarditis, which is one acquired cardiac disease associated with SCD. The coronavirus 2019 (COVID-19) pandemic has therefore resulted in an increased incidence of an otherwise less common condition, providing an expanded dataset for further study of this condition. Recent findings indicate that cardiac complications of athletes with myocardial involvement of SARS-CoV-2 infection are rare. Other contemporary work in SCD screening has been focused on the implementation of various screening protocols and measuring their effectiveness. Summary: No universal consensus exists for athlete screening for conditions associated with SCD with varying guidelines and protocols across cardiology and sport-specific organizations. No screening program will prevent all SCD; however, small programs managed by physicians familiar with the examination of an athlete that carefully personalize screening to the individual may maximize detection of dangerous cardiac conditions while minimizing false positives.

Safety and efficacy of ultrafiltration versus diuretics in patients with decompensated heart failure: A systematic review and meta-analysis.

BACKGROUND: Ultrafiltration (UF) is used for fluid removal patients with acute decompensated heart failure with reduced ejection fraction (HFrEF) refractory to diuretics. However, data on the relative merits of UF and diuretics are limited. METHODS: Online databases were queried to identify clinical trials on the comparison of UF and diuretics. The major adverse cardiovascular (MACE) and its components (mortality and re-hospitalizations) were compared using the random-effects model to calculate the unadjusted odds ratio (OR) with its 95% confidence interval (CI). RESULTS: A total of 10 clinical trials comprising 838 patients (413 UF, 425 diuretics) were included in the analysis. At a median follow-up of 90 days, there was no significant difference in the odds of MACE (OR 0.71, 95% CI 0.47-1.07) and all-cause mortality (OR 1.08, 95% CI 0.77-1.52) between patients undergoing UF compared with those receiving diuretics therapy. The need for emergency department visits (OR 1.05, 95% CI 0.38-2.90), all-cause admissions (OR 0.97, 95% CI 0.72-1.30) and heart failure-related re-hospitalization (OR 0.47, 95% CI 0.21-1.02) was also similar between the two groups. The in-hospital risk for hypotension (OR 0.49, 0.23-1.04) and post-therapy creatinine rise>0.3 mg/dL (OR 1.18, 95% CI 0.74-1.89) was also not significantly different between the UF and diuretics arms. A sensitivity analysis of MACE and mortality did not show any deviation from the pooled outcomes. CONCLUSIONS: In patients with HFrEF, UF appears to be safe but might not provide significant benefits in terms of reducing the risk of mortality or readmission rates compared with those treated with diuretics.