Transthyretin V142I Genetic Variant and Cardiac Remodeling, Injury, and Heart Failure Risk in Black Adults

OBJECTIVES

This study evaluated the association of transthyretin (TTR) gene variant, in which isoleucine substitutes for valine at position 122 (V142I), with cardiac structure, function, and heart failure (HF) risk among middle-aged Black adults.

BACKGROUND

The valine-to-isoleucine substitution in the TTR protein is prevalent in Black individuals and causes cardiac amyloidosis.

METHODS

Jackson Heart Study participants without HF at baseline who had available data on the TTR V142I variant were included. The association of the TTR V142I variant with baseline echocardiographic parameters and repeated measures of high-sensitivity cardiac troponin-I (hs-cTnI) was assessed using adjusted linear regression models and linear mixed models, respectively. Adjusted Cox models, restricted mean survival time analysis, and Anderson-Gill models were constructed to determine the association of TTR V142I variant with the risk of incident HF, survival free of HF, and total HF hospitalizations.

RESULTS

A total of 119 of 2,960 participants (4%) were heterozygous carriers of the TTR V142I variant. The TTR V142I variant was not associated with measures of cardiac parameters at baseline but was associated with a greater increase in high-sensitivity troponin I (hs-TnI) levels over time. In adjusted Cox models, TTR V142I variant carriers had significantly higher risk of incident HF (HR: 1.80; 95% CI: 1.07-3.05; P = 0.03), lower survival free of HF (mean difference: 4.0 year; 95% CI: 0.6-6.2 years); P = 0.02), and higher risk of overall HF hospitalizations (HR: 2.12; 95% CI: 1.23-3.63; P = 0.007).

CONCLUSIONS

The TTR V142I variant in middle-aged Black adults is not associated with adverse cardiac remodeling but was associated with a significantly higher burden of chronic myocardial injury, and greater risk of incident HF and overall HF hospitalizations.

Sustained results of robotic mitral repair in a lower volume center with extensive minimally invasive mitral repair experience

The literature for robotic mitral repair is dominated by a small number of large volume institutions, and intermediate-term outcomes out to 5 years are rare. Whether and under what circumstances a lower volume institution could obtain durable outcomes is not known. A retrospective review was performed on all 133 patients undergoing robotically assisted mitral repair from 2011 to 2019 at a single institution. Mean volume of robotic mitral repair was 16 ± 7 cases per year, while mean institutional total volume of mitral repair was 116 ± 16 cases per year. Mean age was 58 ± 12 years, 77% were men, and mitral etiology was prolapse in 90%. Comorbidity was infrequent with atrial fibrillation in 20% and moderate tricuspid regurgitation in 14%. Central aortic cannulation was used in 97% with concurrent tricuspid operation in 5% and concurrent maze in 14%. Median clamp time, pump time, and length of stay were 146 min, 265 min, and 5 days, respectively, but none improved with experience. There were no deaths or stroke. At 5 years, the cumulative incidence of moderate mitral regurgitation was 18 ± 6% (prolapse patients 11 ± 5%), severe regurgitation 4 ± 3%, and mitral replacement 9 ± 5% (prolapse patients 5 ± 3%). 5-year survival was 96 ± 3%. At centers with significant mitral repair volume, a volume of 16 robotic mitral cases/year can yield good clinical outcomes durable out to 5 years. A case volume of 16 cases per year was not sufficient to improve pump time or length of stay over time.

Robotic versus port-access mitral repair: A propensity score analysis

BACKGROUND

Port-access (PORT) and robotic (ROBO) mitral repair are well established, but differences in patient selection and outcomes are not well documented.

METHODS

A retrospective analysis was performed on 129 ROBO and 628 PORT mitral repairs at one institution. ROBO patients had 4 cm nonrib spreading incisions with robotic assistance, while PORT patients had 6-8 cm rib spreading incisions with thoracoscopic assistance. Propensity score analysis matched patients for differences in baseline characteristics.

RESULTS

Unmatched ROBO patients were younger (58 ± 11 vs. 61 ± 13, p = .05), had a higher percentage of males (77% vs. 63%, p = .003) and had less NYHA Class 3-4 symptoms (11% vs. 21%, p < .01), less atrial fibrillation (19% vs. 29%, p = .02) and less tricuspid regurgitation (14% vs. 24%, p = .01). Propensity score analysis of matched patients showed that pump time (275 ± 57 vs. 207 ± 55, p < .0001) and clamp time (152 ± 38 vs. 130 ± 34, p < .0001) were longer for ROBO patients. However, length of stay, postoperative morbidity, and 5-year survival (97 ± 1% vs. 96 ± 3%, p = .7) were not different. For matched patients with degenerative valve disease, 5-year incidence of mitral reoperation (3 ± 2% vs. 1 ± 1%), severe mitral regurgitation (MR) (6 ± 4% vs. 1 ± 1%), or ≥2 + MR (12 ± 5% vs. 12 ± 4%), were not significantly different between ROBO versus PORT approaches. Predictors of recurrent moderate MR were connective tissue disease, functional etiology, and non-White race, but not surgical approach.

CONCLUSIONS

In this first comparison out to 5 years, robotic versus port-access approach to mitral repair had longer pump and clamp times. Perioperative morbidity, 5-year survival, and 5-year repair durability were otherwise similar.

Contemporary Use of Venoarterial Extracorporeal Membrane Oxygenation: Insights from the Multicenter RESCUE Registry

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used as a life-saving therapy for patients with cardiovascular collapse, but identifying patients unlikely to benefit remains a challenge.

METHODS AND RESULTS

We created the RESCUE registry, a retrospective, observational registry of adult patients treated with VA-ECMO between January 2007 and June 2017 at 3 high-volume centers (Columbia University, Duke University, and Washington University) to describe short-term patient outcomes. In 723 patients treated with VA-ECMO, the most common indications for deployment were postcardiotomy shock (31%), cardiomyopathy (including acute heart failure) (26%), and myocardial infarction (17%). Patients frequently suffered in-hospital complications, including acute renal dysfunction (45%), major bleeding (41%), and infection (33%). Only 40% of patients (n = 290) survived to discharge, with a minority receiving durable cardiac support (left ventricular assist device [n = 48] or heart transplantation [n = 7]). Multivariable regression analysis identified risk factors for mortality on ECMO as older age (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.12-1.42) and female sex (OR, 1.44; 95% CI, 1.02-2.02) and risk factors for mortality after decannulation as higher body mass index (OR 1.17; 95% CI, 1.01-1.35) and major bleeding while on ECMO support (OR, 1.92; 95% CI, 1.23-2.99).

CONCLUSIONS

Despite contemporary care at high-volume centers, patients treated with VA-ECMO continue to have significant in-hospital morbidity and mortality. The optimization of outcomes will require refinements in patient selection and improvement of care delivery.

Cause of Death in Patients With Acute Heart Failure: Insights From RELAX-AHF-2

OBJECTIVES

This study sought to better understand the discrepant results of 2 trials of serelaxin on acute heart failure (AHF) and short-term mortality after AHF by analyzing causes of death of patients in the RELAX-AHF-2 (Efficacy, Safety and Tolerability of Serelaxin When Added to Standard Therapy in AHF-2) trial.

BACKGROUND

Patients with AHF continue to suffer significant short-term mortality, but limited systematic analyses of causes of death in this patient population are available.

METHODS

Adjudicated cause of death of patients in RELAX-AHF-2, a randomized, double-blind, placebo-controlled trial of serelaxin in patients with AHF across the spectrum of ejection fraction (EF), was analyzed.

RESULTS

By 180 days of follow-up, 11.5% of patients in RELAX-AHF-2 died, primarily due to heart failure (HF) (38% of all deaths). Unlike RELAX-AHF, there was no apparent effect of treatment with serelaxin on any category of cause of death. Older patients (≥75 years) had higher rates of mortality (14.2% vs. 8.8%) and noncardiovascular (CV) death (27% vs. 19%) compared to younger patients. Patients with preserved EF (≥50%) had lower rates of HF-related mortality (30% vs. 40%) but higher non-CV mortality (36% vs. 20%) compared to patients with reduced EF.

CONCLUSIONS

Despite previous data suggesting benefit of serelaxin in AHF, treatment with serelaxin was not found to improve overall mortality or have an effect on any category of cause of death in RELAX-AHF-2. Careful adjudication of events in the serelaxin trials showed that older patients and those with preserved EF had fewer deaths from HF or sudden death and more deaths from other CV causes and from noncardiac causes. (Efficacy, Safety and Tolerability of Serelaxin When Added to Standard Therapy in AHF [RELAX-AHF-2]; NCT01870778).

Cardiac Implantable Electronic Devices: A Window Into the Evolution of Conduction Disease in Cardiac Amyloidosis

OBJECTIVES

This study characterized the relationship between conduction disease and cardiac amyloidosis (CA) through longitudinal analysis of cardiac implantable electronic device (CIED) data.

BACKGROUND

Bradyarrhythmias and tachyarrhythmias are commonly reported in CA and may precede a CA diagnosis, although the natural history of conduction disease in CA is not well-described.

METHODS

Patients with CA (transthyretin amyloidosis cardiomyopathy [ATTR-CM] and light-chain amyloidosis [AL-CA]) and a CIED were identified within the Duke University Health System. Patient characteristics at the time of implantation, including demographics and data relevant to CA diagnosis, cardiac imaging, and CIED were recorded. CIED interrogations were analyzed for pacing and atrial fibrillation (AF) burden, activity level, lead parameters, and ventricular arrhythmia incidence and/or therapy.

RESULTS

Thirty-four patients with CA (7 with AL-CA, 27 with ATTR-CM [78% with wild-type]; 82% men) with median age of 75 years and a mean ejection fraction of 42 ± 13% had a CIED implanted for bradycardia (65%) or prevention of sudden cardiac death (35%). CIED implantation preceded CA diagnosis in 14 patients (41%). Over a mean follow-up of 3.1 ± 4.0 years, right ventricular sensing amplitudes decreased but did not result in device malfunction; lead impedances and capture thresholds remained stable. Between post-implantation years 1 and 5, mean ventricular pacing increased from 56 ± 9% to 96 ± 1% (p = 0.003) and AF burden increased from 2 ± 1.3 to 17 ± 3 h/day (p = 0.0002). Ventricular arrhythmias were common (mean episodes per patient per year: 6.7 ± 2.3 [ATTR-CM] and 5.1 ± 3.2 [AL-CA]) but predominately nonsustained; only 1 patient with AL-CA required implantable cardioverter-defibrillator therapy.

CONCLUSIONS

Longitudinal analysis of CIED data in patients with CA revealed progressive conduction disease, with high AF burden and eventual dependence on ventricular pacing, although lead parameters remained stable. Ventricular arrhythmias were common but predominantly nonsustained, particularly in ATTR-CM.

Cardiac Arrest in the Setting of Diffuse Coronary Ectasia: Perspectives on a Unique Ischemic Insult

A 69-year-old man with a history of coronary artery ectasia, potentially resulting from an underlying heritable connective tissue disorder, presented with ventricular fibrillation. Despite medical management of ischemia, he developed recurrent ventricular tachycardia with poor neurological recovery. We highlight challenges in the management of coronary artery ectasia. (Level of Difficulty: Beginner.).

Biomarkers in Advanced Heart Failure: Implications for Managing Patients With Mechanical Circulatory Support and Cardiac Transplantation

Biomarkers have a well-defined role in the diagnosis and management of chronic heart failure, but their role in patients with left ventricular assist devices and cardiac transplant is uncertain. In this review, we summarize the available literature in this patient population, with a focus on clinical application. Some ubiquitous biomarkers, for example, natriuretic peptides and cardiac troponin, may assist in the diagnosis of left ventricular assist device complications and transplant rejection. Novel biomarkers focused on specific pathological processes, such as left ventricular assist device thrombosis and profiling of leukocyte activation, continue to be developed and show promise in altering the management of the advanced heart failure patient. Few biomarkers at this time have been assessed with sufficient scrutiny to warrant broad, universal application, but encouraging limited data and large potential for impact should prompt ongoing investigation.

A care pathway for the cardiovascular complications of COVID-19: Insights from an institutional response

The infection caused by severe acute respiratory syndrome coronavirus-2, or COVID-19, can result in myocardial injury, heart failure, and arrhythmias. In addition to the viral infection itself, investigational therapies for the infection can interact with the cardiovascular system. As cardiologists and cardiovascular service lines will be heavily involved in the care of patients with COVID-19, our division organized an approach to manage these complications, attempting to balance resource utilization and risk to personnel with optimal cardiovascular care. The model presented can provide a framework for other institutions to organize their own approaches and can be adapted to local constraints, resource availability, and emerging knowledge.

Outcomes following cardioversion for patients with cardiac amyloidosis and atrial fibrillation or atrial flutter

Atrial arrhythmias commonly occur in patients with cardiac amyloidosis (CA), but there is limited data on safety or efficacy of cardioversion (DCCV) for management of these rhythms in CA. We identified 25 patients with CA (20 with transthyretin (TTR) and 5 with light-chain (AL) amyloidosis) at Duke University who underwent DCCV for atrial arrhythmias and documented procedural success, complications, and long-term morbidity and mortality. While DCCV successfully restored sinus rhythm in 96% of patients, 36% of patients experienced immediate procedural complications (primarily bradycardia and hypotension), 80% had recurrence of atrial arrhythmias at 1 year, and 52% died at 3 years, highlighting short-term safety concerns, long-term inefficacy, and poor prognosis associated with symptomatic atrial arrhythmias requiring DCCV in CA.

Best Practices for Prognostic Evaluation of a Patient With Transthyretin Amyloid Cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) has emerged as an increasingly identified etiology of heart failure. Fortunately, the disease now has an approved therapy, with many others under development. Assessment of prognosis in ATTR-CM is critical to inform patients about the disease course and guide clinical decisions. This review discusses the evidence behind clinical, biomarker, and imaging findings that inform prognosis in patients with ATTR-CM and can assist providers in the shared decision-making process during management of this disease.

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Prognostic factors for ATTR-CM can guide patient expectations and inform clinical decisions.

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Clinical features, blood biomarkers, and imaging obtained during workup for ATTR-CM convey prognostic information.

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Further studies in determining the incremental value of prognostic factors are warranted.