Characterisation of hypertensive heart disease: pathological insights from a sudden cardiac death cohort to inform clinical practice

The impact of short-term exposure to meteorological factors on the risk of death from hypertension and its major complications: a time series analysis based on Hefei, China

OBJECTIVES

This study aimed to reveal the short-term impact of meteorological factors on the mortality risk in hypertensive patients, providing a scientific foundation for formulating pertinent prevention and control policies.

METHODS

In this research, meteorological factor data and daily death data of hypertensive patients in Hefei City from 2015 to 2018 were integrated. Time series analysis was performed using distributed lag nonlinear model (DLNM) and generalized additive model (GAM). Furthermore, we conducted stratified analysis based on gender and age. Relative risk (RR) combined with 95% confidence interval (95% CI) was used to represent the mortality risk of single day and cumulative day in hypertensive patients.

RESULTS

Single-day lag results indicated that high daily mean temperature (T mean) (75th percentile, 24.9 °C) and low diurnal temperature range (DTR) (25th percentile, 4.20 °C) levels were identified as risk factors for death in hypertensive patients (maximum effective RR values were 1.144 and 1.122, respectively). Extremely high levels of relative humidity (RH) (95th percentile, 94.29%) reduced the risk of death (RR value was 0.893). The stratified results showed that the elderly and female populations are more susceptible to low DTR levels, whereas extremely high levels of RH have a more significant protective effect on both populations.

CONCLUSION

Overall, we found that exposure to low DTR and high T mean environments increases the risk of death for hypertensive patients, while exposure to extremely high RH environments significantly reduces the risk of death for hypertensive patients. These findings contribute valuable insights for shaping targeted prevention and control strategies.

Myocardial Interstitial Fibrosis in Hypertensive Heart Disease: From Mechanisms to Clinical Management

Hypertensive heart disease (HHD) can no longer be considered as the beneficial adaptive result of the hypertrophy of cardiomyocytes in response to pressure overload leading to the development of left ventricular hypertrophy. The current evidence indicates that in patients with HHD, pathological lesions in the myocardium lead to maladaptive structural remodeling and subsequent alterations in cardiac function, electrical activity, and perfusion, all contributing to poor outcomes. Diffuse myocardial interstitial fibrosis is probably the most critically involved lesion in these disorders. Therefore, in this review, we will focus on the histological characteristics, the mechanisms, and the clinical consequences of myocardial interstitial fibrosis in patients with HHD. In addition, we will consider the most useful tools for the noninvasive diagnosis of myocardial interstitial fibrosis in patients with HHD, as well as the most effective available therapeutic strategies to prevent its development or facilitate its regression in this patient population. Finally, we will issue a call to action for the need for more fundamental and clinical research on myocardial interstitial fibrosis in HHD.

Obesity Cardiomyopathy in Sudden Cardiac Death: A Distinct Entity? A Comparative Study

Background

Obesity cardiomyopathy (OCM) can be associated with sudden cardiac death (SCD) but its pathologic features are not well described.

Objectives

The objective of this study was to characterize the clinical and pathological features of OCM associated with SCD.

Methods

This was a retrospective case control autopsy study. OCM was identified by an increased heart weight (>550 g in males; >450 g in females) in individuals with obesity (body mass index [BMI] ≥30 kg/m2) in the absence of other causes. Cases of OCM with SCD were compared to sex and age matched SCD controls with obesity or with normal weight (BMI 18.5-24.9 kg/m2) and morphologically normal hearts. Autopsy measures included: heart weight, atrial dimensions, ventricular wall thickness, and epicardial adipose tissue. Fibrosis was assessed microscopically.

Results

Of 6,457 SCD cases, 53 cases of OCM were identified and matched to 106 controls with obesity and 106 normal weight controls. The OCM mean age at death of individuals with OCM was 42 ± 12 with a male predominance (n = 34, 64%). Males died younger than females (40 ± 13 vs 45 ± 10, P = 0.036). BMI was increased in OCM cases compared to controls with obesity (42 ± 8 vs 35 ± 5). The average heart weight was 598 ± 93 g in OCM. There were increases in right and left ventricular wall thickness (all P < 0.05) in OCM cases compared to controls. Right ventricular epicardial fat was increased in OCM compared to normal weight controls only. Left ventricular fibrosis was identified in 7 (13%) cases.

Conclusions

OCM may be a specific pathological entity associated with SCD. It is most commonly seen in young males with increased BMI.

Genetically determined cardiomyopathies at autopsy: the pivotal role of the pathologist in establishing the diagnosis and guiding family screening

Cardiomyopathies (CMP) comprise a heterogenous group of diseases affecting primarily the myocardium, either genetic and/or acquired in origin. While many classification systems have been proposed in the clinical setting, there is no internationally agreed pathological consensus concerning the diagnostic approach to inherited CMP at autopsy. A document on autopsy diagnosis of CMP is needed because the complexity of the pathologic backgrounds requires proper insight and expertise. In cases presenting with cardiac hypertrophy and/or dilatation/scarring with normal coronary arteries, a suspicion of inherited CMP must be considered, and a histological examination is essential. Establishing the actual cause of the disease may require a number of tissue-based and/or fluid-based investigations, be it histological, ultrastructural, or molecular. A history of illicit drug use must be looked for. Sudden death is frequently the first manifestation of disease in case of CMP, especially in the young. Also, during routine clinical or forensic autopsies, a suspicion of CMP may arise based on clinical data or pathological findings at autopsy. It is thus a challenge to make a diagnosis of a CMP at autopsy. The pathology report should provide the relevant data and a cardiac diagnosis which can help the family in furthering investigations, including genetic testing in case of genetic forms of CMP. With the explosion in molecular testing and the concept of the molecular autopsy, the pathologist should use strict criteria in the diagnosis of CMP, and helpful for clinical geneticists and cardiologists who advise the family as to the possibility of a genetic disease.

Growing Heart Failure Burden of Hypertensive Heart Disease: A Call to Action

Hypertensive heart disease (HHD) is currently the second leading cause of heart failure. The prevalence of HHD and its associated risk of heart failure have increased despite substantial improvement in arterial hypertension treatment and control in the recent decades. Therefore, the prevention of heart failure in patients with HHD represents an unmet medical need, due to its clinical, economic, and social impact. In this conceptual framework, we call to action because the time has come for diagnosis and treatment of patients with HHD not to be limited to assessment of morphological and functional left ventricular changes, blood pressure control, and left ventricular hypertrophy regression. We propose a further perspective incorporating also the detection and reversal of the histological changes that develop in the hypertensive heart and that lead to the structural remodeling of the myocardium. In particular, we focus on the diagnosis and treatment of myocardial interstitial fibrosis, likely the lesion most critically involved in the transition from subclinical HHD to clinically overt heart failure. In this context, it is worth considering whether the use of imaging and circulating biomarkers for the noninvasive diagnosis of myocardial interstitial fibrosis should be incorporated in the medical study of hypertensive patients, especially of those with HHD.

Of Mouse and Man: Cross-Species Characterization of Hypertensive Cardiac Remodeling

Hypertension is a major public health concern and poses a significant risk for sudden cardiac death (SCD). However, the characterisation of human tissues tends to be macroscopic, with little appreciation for the quantification of the pathological remodelling responsible for the advancement of the disease. While the components of hypertensive remodelling are well established, the timeline and comparative quantification of pathological changes in hypertension have not been shown before. Here, we sought to identify the phasing of cardiac remodelling with hypertension using post-mortem tissue from SCD patients with early and advanced hypertensive heart disease (HHD). In order to study and quantify the progression of phenotypic changes, human specimens were contrasted to a well-described angiotensin-II-mediated hypertensive mouse model. While cardiomyocyte hypertrophy is an early adaptive response in the mouse that stabilises in established hypertension and declines as the disease progresses, this finding did not translate to the human setting. In contrast, optimising fibrosis quantification methods and applying them to each setting identified perivascular fibrosis as the prevailing possible cause for overall disease progression. Indeed, assessing myocardial inflammation highlights CD45+ inflammatory cell infiltration that precedes fibrosis and is an early-phase event in response to elevated arterial pressures that may underscore perivascular remodelling. Along with aetiology insight, we highlight cross-species comparison for quantification of cardiac remodelling in human hypertension. As such, this platform could assist with the development of therapies specific to the disease phase rather than targeting global components of hypertension, such as blood pressure lowering.

Cardiac pathology in COVID-19: a single center autopsy experience

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is commonly associated with myocardial injury and heart failure. The pathophysiology behind this phenomenon remains unclear, with many diverse and multifaceted hypotheses. To contribute to this understanding, we describe the underlying cardiac findings in fifty patients who died with coronavirus disease 2019 (COVID-19).

Methods

Included were autopsies performed on patients with a positive SARS-CoV-2 reverse-transcriptase-polymerase-chain reaction test from the index hospitalization. In the case of out-of-hospital death, patients were included if post-mortem testing was positive. Complete autopsies were performed according to a COVID-19 safety protocol, and all patients underwent both macroscopic and microscopic examination. If available, laboratory findings and echocardiograms were reported.

Results

The median age of the decedents was 63.5 years. The most common comorbidities included hypertension (90.0%), diabetes (56.0%) and obesity (50.0%). Lymphocytic inflammatory infiltrates in the heart were present in eight (16.0%) patients, with focal myocarditis present in two (4.0%) patients. Acute myocardial ischemia was observed in eight (16.0%) patients. The most common findings were myocardial fibrosis (80.0%), hypertrophy (72.0%), and microthrombi (66.0%). The most common causes of death were COVID-19 pneumonia in 18 (36.0%), COVID-19 pneumonia with bacterial superinfection in 12 (24.0%), and COVID-19 pneumonia with pulmonary embolism in 10 (20.0%) patients.

Conclusions

Cardiovascular comorbidities were prevalent, and pathologic changes associated with hypertensive and atherosclerotic cardiovascular disease were the most common findings. Despite markedly elevated inflammatory markers and cardiac enzymes, few patients exhibited inflammatory infiltrates or necrosis within cardiac myocytes. A unifying pathophysiologic mechanism behind myocardial injury in COVID-19 remains elusive, and additional autopsy studies are needed.