Prognostic prediction of genotype versus phenotype in genetic cardiomyopathies

Background

In cardiomyopathies (CMPs), the diverse genetic background often leads to phenotypic heterogeneity. Currently, genotype-phenotype studies are founded on clinical phenotype-based classification of CMPs, contributing possible biases due to the exclusion of specific and unascertained phenotypic expressions of CMP genes.

Purpose

We sought to define differences in outcome when stratifying patients based on phenotype at presentation compared with genotype in a large cohort of CMP patients with positive genetic testing.

Methods

In this study, we included the whole spectrum of non-hypertrophic CMP phenotypes, genetically determined: dilated cardiomyopathy (DCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), left ventricular arrhythmogenic cardiomyopathy (ALVC) and biventricular ARVC (BiV). The primary and secondary outcomes were: 1) all-cause mortality/heart transplant (D/HT); 2) heart failure-related death/heart transplant/left ventricular assist device implantation (DHF/HT/VAD); and 3) sudden cardiac death/life-threatening ventricular arrhythmias (SCD/MVA).

Results

Two hundred and eighty-one patients (80% DCM) carrying pathogenic or likely pathogenic variants were included in this study. The phenotype was classified as DCM, ARVC, ALVC and BiV according to current consensus criteria. The median follow-up was 188 months. Variants in titin (TTN; 34%) and sarcomeric genes (SARC; 22%) were the most frequent genotypes and almost invariably associated with a DCM phenotype. DSP, LMNA and FLNC displayed more heterogeneous phenotypic presentations, including DCM, ARVC, ALVC, BiV. At survival analysis, the arrhythmic outcome occurred more frequently in patients without a DCM phenotype and in carriers of DSP, PKP2, LMNA and FLNC variants. However, after adjustment for age and sex, the genotype-based classification but not the phenotype-based classification was predictive of the arrhythmic outcome. LMNA showed the worst trend in term of D/HT and DHF/HT/LVAD.

Conclusions

In genetic cardiomyopathies, genotype is associated with significant phenotypic heterogeneity. Nevertheless, in our study, the genotypic-based classification showed higher precision in predicting CMP patients' outcome in respect to the phenotype-based classification. These findings add to the current understanding of inherited CMPs and may implement the risk stratification of patients with positive genetic testing.

Funding Acknowledgement

Type of funding sources: None.

P205 PROGNOSTIC VALUE OF AMYLOID–Β (1–40) IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION

Background

Survivors of acute myocardial infarction (AMI) have an increased risk of various cardiovascular complications during follow–up; therefore, adequate risk stratification remains the main challenge in the clinical setting. Amyloid β 1–40 (Aβ (1–40)) has already emerged as a negative prognostic marker for cardiovascular mortality, both in patients with stable chronic coronary artery disease and in patients with NSTEMI–type infarction. This is probably due to the pro–inflammatory and pro–atherosclerotic role of this peptide.

Methods

Plasma Aβ (1–40) values were tested acutely in a large prospective cohort of patients hospitalized for AMI (both NSTEMI and STEMI). The primary end–point was defined as all–cause mortality during the period of follow–up.

Results

894 individuals were enrolled in the study (607 with STEMI and 287 with NSTEMI). The median plasma concentration of Aβ (1–40) at the time of admission was 96.59 (60.94–134.5) pg/ml. During a median follow–up of 43 months, 123 patients died (primary endpoint). Higher Aβ (1–40) concentrations were associated with an increased risk of mortality, both on univariate analysis and after correction for other confounding variables. Furthermore, we found a strong positive correlation between plasma Aβ (1–40) values and age. The prognostic value of Aβ (1–40) was maintained only in the subgroup of patients with greater than the median age of 67 years.

Conclusions

This is currently the largest single–centre study evaluating the role of plasma Aβ (1–40) concentrations in predicting outcome in a population of patients admitted for AMI, both STEMI and NSTEMI. Our data represent a strong correlation between plasma (1–40) values and the increased risk of all–cause mortality during follow–up.

Global longitudinal strain by CMR improves prognostic stratification in acute myocarditis presenting with normal LVEF

Funding Acknowledgements

Type of funding sources: None.

Background

Prognostic stratification of acute myocarditis (AM) presenting with normal left ventricular ejection fraction (LVEF) relies mostly on late gadolinium enhancement (LGE) characterization (1).

Purpose

Left ventricular peak global longitudinal strain (LV-GLS) measured by feature tracking analysis might improve prognostication of AM presenting with normal LVEF (2,3).

Methods

Data of patients undergoing cardiac magnetic resonance (CMR) for clinically suspected AM in seven European Centres (2013-2020) were retrospectively analysed. Patients with AM confirmed by CMR and LVEF ≥50% were included. LGE was visually characterized: localized vs. diffuse, subepicardial vs midwall. LV-GLS was measured by dedicated software. The primary outcome was the first occurrence of an adverse cardiovascular event (ACE) including cardiac death, life-threatening arrhythmias, development of heart failure or of LVEF <50%.

Results

Of 389 screened patients, 256 (66%) fulfilled inclusion criteria: median age 36 years, 71% males, median LVEF 60%, median LV-GLS -17.3%. CMR was performed at 4 [2-12] days from hospitalization. At 27 months, 24 (9%) patients experienced ≥1 ACE (71% developed LVEF <50%). Compared to the others, patients experiencing ACEs had lower median LV-GLS values (-13.9% vs -17.5%, p=0.001). At Kaplan-Meier analysis, impaired LV-GLS (both considered as >-20% or quartiles), diffuse and midwall LGE were associated with ACEs (Figure 1). Patients with LV-GLS ≤-20% did not experience ACEs. LV-GLS remained associated with ACEs after adjustment for diffuse and midwall LGE.

Conclusions

In AM presenting with LVEF ≥50%, LV-GLS provides independent prognostic value over LGE characterization, improving risk stratification and representing a rationale for further studies of therapy in this cohort (Figure 2).

Prognostic implications of previously known or newly diagnosed diabetes and hypovitaminosis D in patients with myocardial infarction

Background

Vitamin D deficiency and diabetes mellitus are frequent among patients with acute myocardial infarction. Independently, both were associated with a worse prognosis after myocardial infarction (MI). However, it is unclear whether the risk of worse outcome, associated with diabetes mellitus, may be accentuated in presence of hypovitaminosis D.

Purpose

We assessed if previously known or newly diagnosed diabetes is associated with worse outcome (major cardiovascular events) in combination with hypovitaminosis D in patients with acute MI.

Methods and results

Were enrolled 1004 patients with acute MI; 64.7% of them, had hypovitaminosis D and 37% were diabetic.

We grouped our population by diabetic status: previously known diabetes (diagnosis of diabetes before MI, n=330; 32.9%); newly diagnosed diabetes (during hospitalization for MI, but no known diabetes at presentation, n=47; 4.7%); or no diabetes (n=627; 62.5%).

Hypovitaminosis D was more frequent among patients with previously known (70.2%) and newly diagnosed diabetes (73.3%), when compared to non diabetic patients (61.2%).

During median follow-up of 15.6 months, patients with previously known and newly diagnosed diabetes had increased risks of major cardiovascular events (HR 1.72; 95% CI, 1.26 to 2.36. The risk of major events during the follow-up among diabetic patients, was further increased in presence of hypovitaminosis D (Figure 1).

Conclusions

The presence of both, previously known or newly diagnosed diabetes and hypovitaminosis D, in patients with MI is synergistically associated with a worse outcome.

Funding Acknowledgement

Type of funding source: None

COVID-19 and renin-angiotensin system inhibition: role of angiotensin converting enzyme 2 (ACE2) - Is there any scientific evidence for controversy?

Renin-angiotensin system (RAS) blockers are extensively used worldwide to treat many cardiovascular disorders, where they are effective in reducing both mortality and morbidity. These drugs are known to induce an increased expression of angiotensin-converting enzyme 2 (ACE2). ACE2 acts as receptor for the novel SARS coronavirus-2 (SARS-CoV-2) which raising the important issue of possible detrimental effects that RAS blockers could exert on the natural history and pathogenesis of the coronavirus disease-19 (COVID-19) and associated excessive inflammation, myocarditis and cardiac arrhythmias. We review the current knowledge on the interaction between SARS-CoV-2 infection and RAS blockers and suggest a scientific rationale for continuing RAS blockers therapy in patients with COVID-19 infection.