Background

Blood donor screening leads to large numbers of new diagnoses of Trypanosoma cruzi infection, with most donors in the asymptomatic chronic indeterminate form. Information on electrocardiogram (ECG) findings in infected blood donors is lacking and may help in counseling and recognizing those with more severe disease.

Objectives

To assess the frequency of ECG abnormalities in T.cruzi seropositive relative to seronegative blood donors, and to recognize ECG abnormalities associated with left ventricular dysfunction.

Methods

The study retrospectively enrolled 499 seropositive blood donors in São Paulo and Montes Claros, Brazil, and 483 seronegative control donors matched by site, gender, age, and year of blood donation. All subjects underwent a health clinical evaluation, ECG, and echocardiogram (Echo). ECG and Echo were reviewed blindly by centralized reading centers. Left ventricular (LV) dysfunction was defined as LV ejection fraction (EF)<0.50%.

Results

Right bundle branch block and left anterior fascicular block, isolated or in association, were more frequently found in seropositive cases (p<0.0001). Both QRS and QTc duration were associated with LVEF values (correlation coefficients -0.159,p<0.0003, and -0.142,p = 0.002) and showed a moderate accuracy in the detection of reduced LVEF (area under the ROC curve: 0.778 and 0.790, both p<0.0001). Several ECG abnormalities were more commonly found in seropositive donors with depressed LVEF, including rhythm disorders (frequent supraventricular ectopic beats, atrial fibrillation or flutter and pacemaker), intraventricular blocks (right bundle branch block and left anterior fascicular block) and ischemic abnormalities (possible old myocardial infarction and major and minor ST abnormalities). ECG was sensitive (92%) for recognition of seropositive donors with depressed LVEF and had a high negative predictive value (99%) for ruling out LV dysfunction.

Conclusions

ECG abnormalities are more frequent in seropositive than in seronegative blood donors. Several ECG abnormalities may help the recognition of seropositive cases with reduced LVEF who warrant careful follow-up and treatment.

Carney complex (CNC) is a multiple neoplasia syndrome that is caused mostly by PRKAR1A mutations. Cardiac myxomas are the leading cause of mortality in CNC patients who, in addition, often develop growth hormone (GH) excess. We studied patients with CNC, who were observed for over a period of 20 years (1995-2015) for the development of both GH excess and cardiac myxomas. GH secretion was evaluated by standard testing; dedicated cardiovascular imaging was used to detect cardiac abnormalities. Four excised cardiac myxomas were tested for the expression of insulin-like growth factor-1 (IGF-1). A total of 99 CNC patients (97 with a PRKAR1A mutation) were included in the study with a mean age of 25.8 ± 16.6 years at presentation. Over an observed mean follow-up of 25.8 years, 60% of patients with GH excess (n = 46) developed a cardiac myxoma compared with only 36% of those without GH excess (n = 54) (P = 0.016). Overall, patients with GH excess were also more likely to have a tumor vs those with normal GH secretion (OR: 2.78, 95% CI: 1.23-6.29; P = 0.014). IGF-1 mRNA and protein were higher in CNC myxomas than in normal heart tissue. We conclude that the development of cardiac myxomas in CNC may be associated with increased GH secretion, in a manner analogous to the association between fibrous dysplasia and GH excess in McCune-Albright syndrome, a condition similar to CNC. We speculate that treatment of GH excess in patients with CNC may reduce the likelihood of cardiac myxoma formation and/or recurrence of this tumor.

Artificial intelligence (AI) promises to revolutionize many fields, but its clinical implementation in cardiovascular imaging is still rare despite increasing research. We sought to facilitate discussion across several fields and across the lifecycle of research, development, validation, and implementation to identify challenges and opportunities to further translation of AI in cardiovascular imaging. Furthermore, it seemed apparent that a multidisciplinary effort across institutions would be essential to overcome these challenges. This paper summarizes the proceedings of the National Heart, Lung, and Blood Institute-led workshop, creating consensus around needs and opportunities for institutions at several levels to support and advance research in this field and support future translation.

Background

Very few studies have measured disease penetrance and prognostic factors of Chagas cardiomyopathy among asymptomatic Trypanosoma cruzi-infected persons.

Methods and results

We performed a retrospective cohort study among initially healthy blood donors with an index T cruzi-seropositive donation and age-, sex-, and period-matched seronegatives in 1996 to 2002 in the Brazilian cities of São Paulo and Montes Claros. In 2008 to 2010, all subjects underwent medical history, physical examination, ECGs, and echocardiograms. ECG and echocardiogram results were classified by blinded core laboratories, and records with abnormal results were reviewed by a blinded panel of 3 cardiologists who adjudicated the outcome of Chagas cardiomyopathy. Associations with Chagas cardiomyopathy were tested with multivariate logistic regression. Mean follow-up time between index donation and outcome assessment was 10.5 years for the seropositives and 11.1 years for the seronegatives. Among 499 T cruzi seropositives, 120 (24%) had definite Chagas cardiomyopathy, and among 488 T cruzi seronegatives, 24 (5%) had cardiomyopathy, for an incidence difference of 1.85 per 100 person-years attributable to T cruzi infection. Of the 120 seropositives classified as having Chagas cardiomyopathy, only 31 (26%) presented with ejection fraction <50%, and only 11 (9%) were classified as New York Heart Association class II or higher. Chagas cardiomyopathy was associated (P<0.01) with male sex, a history of abnormal ECG, and the presence of an S3 heart sound.

Conclusions

There is a substantial annual incidence of Chagas cardiomyopathy among initially asymptomatic T cruzi-seropositive blood donors, although disease was mild at diagnosis.

Background

Transcatheter mitral valve repair is beneficial in patients with mitral regurgitation (MR), left ventricular dysfunction, and persistent symptoms despite maximally tolerated medical therapy.

Objectives

The aim of this study was to evaluate the safety and feasibility of transcatheter mitral cerclage ventriculoplasty in patients with MR and either heart failure with reduced ejection fraction or preserved ejection fraction and in subjects with prior edge-to-edge repair but persistent or recurrent symptomatic MR.

Methods

The National Heart, Lung, and Blood Institute Division of Intramural Research Transcatheter Mitral Cerclage Ventriculoplasty Early Feasibility Study (NCT03929913) was an investigator-initiated prospective multicenter study. The primary endpoint was technical success measured at exit from the catheterization laboratory. Follow-up included heart failure quality-of-life assessments and serial imaging with echocardiography and cardiac computed tomography.

Results

Nineteen subjects consented and underwent cerclage, 63% with heart failure with reduced ejection fraction and 37% with heart failure with preserved ejection fraction, with ischemic cardiomyopathy in 26% and nonischemic cardiomyopathy in 74%. There were no procedural deaths, strokes, or transient ischemic attacks or other major cardiovascular adverse events. The primary endpoint was met in 17 subjects. Cerclage induced sustained reductions in mitral regurgitant volume (-41%) and effective orifice area (-33%) after a median of 337 days. Cerclage resulted in improvements in 6-minute walking distance (+78 m) and Kansas City Cardiomyopathy Questionnaire Overall Summary Score (+22 points) at 30 days that were maintained after a median of 265 days. New complete heart block developed in 6 of 17 subjects. Three deaths occurred on postprocedural days 79, 159, and 756, unrelated to cerclage.

Conclusions

Transcatheter mitral cerclage ventriculoplasty resulted in significant and sustained improvements in mitral regurgitation and in heart failure quality-of-life assessments.

Through bound apolipoprotein A-I (apoA-I), high-density lipoprotein cholesterol (HDL-C) activates endothelial nitric oxide synthase, inducing vasodilation. Because patients with sickle cell disease (SCD) have low apoA-I and endothelial dysfunction, we conducted a randomized, double-blinded, placebo-controlled trial to test whether extended-release niacin (niacin-ER) increases apoA-I-containing HDL-C and improves vascular function in SCD. Twenty-seven patients with SCD with levels of HDL-C <39 mg/dl or apoA-I <99 mg/dl were randomized to 12 weeks of niacin-ER, increased in 500-mg increments to a maximum of 1,500 mg/day, or placebo. The primary outcome was the absolute change in HDL-C level after 12 weeks, with endothelial function assessed before and at the end of treatment. Niacin-ER-treated patients trended to greater increase in HDL-C level compared with placebo treatment at 12 weeks (5.1 ± 7.7 vs 0.9 ± 3.8 mg/dl, 1-tailed p = 0.07), associated with significantly greater improvements in the ratios of low-density lipoprotein to HDL-C levels (1.24 vs 1.95, p = 0.003) and apolipoprotein B to apoA-I levels (0.46 vs 0.58, p = 0.03) compared with placebo-treated patients. No improvements were detected in 3 independent vascular physiology assays of endothelial function. Thus, the relatively small changes in HDL-C levels achieved by the dose of niacin-ER used in our study are not associated with improved vascular function in patients with SCD with initially low levels of apoA-I or HDL-C.

De novo mutations (DNMs), or mutations that appear in an individual despite not being seen in their parents, are an important source of genetic variation whose impact is relevant to studies of human evolution, genetics, and disease. Utilizing high-coverage whole-genome sequencing data as part of the Trans-Omics for Precision Medicine (TOPMed) Program, we called 93,325 single-nucleotide DNMs across 1,465 trios from an array of diverse human populations, and used them to directly estimate and analyze DNM counts, rates, and spectra. We find a significant positive correlation between local recombination rate and local DNM rate, and that DNM rate explains a substantial portion (8.98 to 34.92%, depending on the model) of the genome-wide variation in population-level genetic variation from 41K unrelated TOPMed samples. Genome-wide heterozygosity does correlate with DNM rate, but only explains <1% of variation. While we are underpowered to see small differences, we do not find significant differences in DNM rate between individuals of European, African, and Latino ancestry, nor across ancestrally distinct segments within admixed individuals. However, we did find significantly fewer DNMs in Amish individuals, even when compared with other Europeans, and even after accounting for parental age and sequencing center. Specifically, we found significant reductions in the number of C→A and T→C mutations in the Amish, which seem to underpin their overall reduction in DNMs. Finally, we calculated near-zero estimates of narrow sense heritability (h²), which suggest that variation in DNM rate is significantly shaped by nonadditive genetic effects and the environment.