Relative contribution of risk factors/co-morbidities to heart failure pathogenesis: interaction with ejection fraction

Back to the basics: The need for an etiological classification of chronic heart failure

The left ventricular (LV) ejection fraction (LVEF), despite its severe limitations, has had an epicentral role in heart failure (HF) classification, management, and risk stratification for decades. The major argument favoring the LVEF based HF classification has been that it defines groups of patients in which treatment is effective. However, this reasoning has recently collapsed, since medical treatment with neurohormonal inhibitors, has proved beneficial in most HF patients regardless of the LVEF. In addition, there has been compelling evidence, that the LVEF provides poor guidance for device treatment of chronic HF (implantation of cardioverter defibrillator, cardiac resynchronization therapy) since sudden cardiac death may occur and cardiac dyssynchronization may be disastrous in all HF patients. The same holds true for LV assist device implantation, in which the LVEF has been used as a surrogate for LV size. In this review article we update the evidence questioning the use of LVEF-based HF classification and argue that guidance of chronic HF treatment should transition to more contemporary concepts. Specifically, we propose an etiologic chronic HF classification predominantly based on epidemiological data, which will be foundational for further higher resolution phenotyping in the emerging era of precision medicine.

Hypertensive Heart Failure

Despite overwhelming epidemiological evidence, the contribution of hypertension (HTN) to heart failure (HF) development has been undermined in current clinical practice. This is because approximately half of HF patients have been labeled as suffering from HF with preserved left ventricular (LV) ejection fraction (EF) (HFpEF), with HTN, obesity, and diabetes mellitus (DM) being considered virtually equally responsible for its development. However, this suggestion is obviously inaccurate, since HTN is by far the most frequent and devastating morbidity present in HFpEF. Further, HF development in obesity or DM is rare in the absence of HTN or coronary artery disease (CAD), whereas HTN often causes HF per se. Finally, unlike HTN, for most major comorbidities present in HFpEF, including anemia, chronic kidney disease, pulmonary disease, DM, atrial fibrillation, sleep apnea, and depression, it is unknown whether they precede HF or result from it. The purpose of this paper is to provide a contemporary overview on hypertensive HF, with a special emphasis on its inflammatory nature and association with autonomic nervous system (ANS) imbalance, since both are of pathophysiologic and therapeutic interest.

Strategic multimodal non-invasive assessment of cardiac performance in patients with heart failure

AIMS

Although various non-invasive cardiac examinations are known to be predictive of long-term outcomes in patients with heart failure (HF), combining them properly would provide synergism. We aimed to show that non-invasive cardiac assessments targeting left ventricular filling pressure (LVFP), left atrial remodelling, and exercise capacity would provide better prognostication in combination.

METHODS AND RESULTS

This prospective observational study included consecutive hospitalized stage A-C HF patients evaluated with N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiography including two-dimensional speckle tracking, and cardiopulmonary exercise testing. According to NT-proBNP and echocardiographic semi-quantitative LVFP grading (Echo-LVFP), patients were classified into three LVFP groups: normal range of both Echo-LVFP and NT-proBNP (Group 1), normal range of Echo-LVFP but elevated NT-proBNP (Group 2), and elevated Echo-LVFP and NT-proBNP (Group 3). The adverse outcome was defined as a composite of cardiovascular death, non-fatal acute coronary syndrome, acute stroke, or HF-related hospitalization. Among 224 HF patients (mean age of 63.8 ± 11.6 years, 158 men) analysed, 160 (71.4%) had ischaemic aetiology. During the follow-up of 18.6 ± 9.8 months, event-free survival in Group 2 (n = 56, age of 65.4 ± 12.4) was better than that in Group 3 (n = 45, age of 68.5 ± 11.5) but worse than that in Group 1 (n = 123, mean age of 61.4 ± 10.5) (log-rank P < 0.001). Mechanical left atrial dysfunction (peak longitudinal strain <28%) (adjusted hazard ratio 5.69, 95% confidence interval 1.06-4.48) and limited exercise capacity (peak VO₂ per +5 mL/kg/min) (adjusted hazard ratio 0.63, 95% confidence interval 0.46-0.87) were also predictable adverse outcomes. Serial addition of peak VO₂ and left atrial strain to the model incrementally enhanced the predictive power of LVFP-based risk stratification for adverse outcomes.

CONCLUSIONS

The combination of NT-proBNP and Echo-LVFP could be used to predict adverse outcomes in patients with HF of various stages. Left atrial mechanics and exercise capacity are incremental to prognostication. Non-invasive test findings could be strategically combined to provide an integrative profile of cardiac performance.

Reshaping Treatment of Heart Failure with Preserved Ejection Fraction

Current data indicate that in the community, approximately 50% of patients with heart failure (HF) have preserved left ventricular (LV) ejection fraction (LVEF)—the so-called HFpEF. Treatment of HFpEF has been considered an unmet need for decades. We believe that the main underlying reasons have been (a) the ever-changing LVEF cut-offs used for HF classification; (b) controversies regarding the definition of the LVEF normal range; (c) the fact that HFpEF does not represent a phenotype, but a category of diseases with entirely different characteristics (hypertensive heart disease, valvular heart disease (VHD), hypertrophic cardiomyopathy (HCM) etc.); (d) the lack of recognition that hypertensive HFpEF is the most common and important HFpEF phenotype; (e) the assumption that neurohormonal overactivity is absent in HF patients with a LVEF > 45−50% which has been proven to be wrong. Current HFpEF trials, in which the vast majority of the participants suffered from hypertension (HTN), whereas VHD and HCM were absent, demonstrated that neurohormonal and sodium-glucose cotransporter 2 (SGLT2) inhibitors are effective in HF patients over a wide LVEF range. Thus, restricting these lifesaving treatments to HF patients with reduced LVEF is not justified anymore and it should be additionally considered for HFpEF patients suffering from HTN.

Myocardial strain in hypertension: a meta-analysis of two-dimensional speckle tracking echocardiographic studies

AIM

Available evidence on systolic dysfunction in systemic hypertension, as assessed by left ventricular (LV) mechanics, is still based on single studies. Thus, we performed a systematic meta-analysis of two-dimensional speckle-tracking studies in order to provide an updated comprehensive information on this issue.

METHODS

The PubMed, OVID-MEDLINE, and Cochrane library databases were analyzed to search English language articles published from the inception up to 31 December 2020. Studies were identified by using MeSH terms and crossing the following search items: 'myocardial strain', 'left ventricular mechanics', 'speckle tracking echocardiography', 'systolic dysfunction', 'hypertensive heart disease', 'systemic hypertension', 'essential hypertension'.

RESULTS

Data from 4276 individuals (2089 normotensive controls and 2187 mostly uncomplicated hypertensive patients) were included. Left ventricular (LV) mass index, relative wall thickness, left atrial volume index and E/e' ratio were significantly higher in hypertensive patients than in normotensive controls. LV ejection fraction did not differ in the two pooled groups (SMD -0.048 ± 0.054, 95% CI -0.20 to 0.10, P = 0.30), whereas LV global longitudinal strain (GLS) was significantly impaired in the hypertensive group (SMD: 1.07 ± 0. 15, 95% CI 0.77-1.36, P < 0.0001). Similar findings were obtained in a sub-analysis restricted to 15 studies in which mean age was similar in cases and controls (SMD 1.21 ± 0.23, 95% CI 0.76-1.67, P = 0.002).

CONCLUSION

The present meta-analysis suggests that GLS assessment unmasks systolic dysfunction undetected by conventional ejection fraction in the uncomplicated hypertension setting and that this parameter should be incorporated into routine work-up aimed to identify hypertension-mediated cardiac damage.

Relative contribution of risk factors/co-morbidities to heart failure pathogenesis: interaction with ejection fraction

Aims

The relative impact of each individual coexisting morbidity on the pathogenesis of heart failure (HF) is incompletely understood. This study aimed to evaluate the prevalence of individual cardiac and non‐cardiac coexisting morbidities both in the overall HF population and in the subgroup of HF patients with a single coexisting morbidity, stratified by left ventricular ejection fraction (LVEF) categories, as a measure of the relative contribution of each co‐morbidity to the pathogenesis of HF.

Methods and results

This is a prospective, observational study, in which unselected ambulatory patients with chronic HF visiting the HF clinic of a tertiary university hospital from January 2016 to January 2019 were classified according to baseline LVEF into three groups: (i) LVEF < 40%, (ii) LVEF = 40–49%, and (iii) LVEF ≥ 50% and then evaluated for various coexisting morbidities. Overall, 1064 patients (age 73.4 ± 12.1 years, male gender 57.7%, LVEF 43.6 ± 13.9, N‐terminal pro‐brain natriuretic peptide 2187 ± 710 ng/L, and estimated glomerular filtration rate 67.2 ± 25 mL/min/1.73 m²) were recruited in this study. Of these, 361 (33.9%) had an LVEF < 40%, 247 (23.2%) an LVEF = 40–49%, and 456 (42.9%) an LVEF ≥ 50%. There were 90 (8.5%) HF patients with a single coexisting morbidity, 33 (36.7%) with LVEF ≥ 50%, 27 (30.0%) with LVEF = 40–49%, and 30 (33.3%) with LVEF < 40%. Among these patients, those with LVEF ≥ 50% suffered mostly from hypertension (85.7%), whereas the second most common coexisting morbidity was atrial fibrillation (AF) (9.5%). HF patients with LVEF = 40–49% usually suffered from hypertension (35.7%), AF (28.6%), or myocardial infarction (MI) (21.4%). Finally, HF patients with LVEF < 40% usually suffered from MI (30.8%), AF (30.8%), or hypertension (15.4%).

Conclusions

Hypertension is strongly associated with the development of HF with low, intermediate, or near‐normal/normal LVEF whereas a history of MI or AF with HF with a low or an intermediate LVEF.