Sex differences in cardiac remodeling post myocardial infarction with acute cigarette smoking

Abstract

Background Whether cigarette smoking affects the heart post-myocardial infarction (MI) in a sex-dependent way remains controversial. Using a mouse model, we investigated cardiac remodeling under the influence of acute cigarette smoke (CS) exposure following ischemic injury in both sexes. Methods Ten cigarettes were smoked twice daily for 2 weeks followed by MI and then 1 additional week post permanent LAD ligation. Cardiac function, histology, and infarct size were assessed, and inflammatory markers quantified by RT–PCR. Statistical comparisons were performed using an unpaired t test or ANOVA followed by Tukey post hoc test. Results We observed that cigarette smoking exacerbated both left and right ventricular remodeling only in males at an early stage of post-MI. Females did not display a significant structural and/or functional alteration within 7 days of cardiac remodeling post-MI upon CS exposure. Worsened right ventricular remodeling in males was independent of pulmonary congestion. CS-exposed males exhibited enhanced increases in left ventricular end systolic and diastolic volumes, as well as reductions in ejection fraction and fractional area changes of left ventricular base. At day 7, infarct size was increased by cigarette smoking in males only, which was accompanied by enhanced collagen deposition in both the infarcted and peri-infarcted areas. Both IL-6 and TNF-α mRNA expression significantly increased in CS-exposed MI male group only at day 7 post-MI suggestive of prolonged inflammation. Conclusions These findings indicate that CS exposure worsens the progression of cardiac remodeling post-MI in male sex in a significant manner compared to female sex at least at early stages.

Association between tobacco smoking and heart disease in older adults: a cross-sectional study based on the Chinese Longitudinal Healthy Longevity Survey

“…Smoking was associated with prevalence of heart disease, with increased risk for women. This was consistent with previous research reporting that women who smoke in China have higher mortality rates and worse prognosis after acute cardiovascular events ( 16 , 22 - 24 ). Based on the impact of smoking on heart disease among females, future health care strategies should address this behavior in women to better control heart disease.…”

“…Cigarette smoking is associated with increased risk of heart disease due to multiple factors, including exposure to hazardous components of tobacco smoke and interactions with various physiologic processes ( 15 , 16 ). Tobacco smoke contains oxidizing chemicals, nicotine, and carbon monoxide, as well as particulates and heavy metals ( 17 ).…”

“…The incidence of heart disease varies considerably by age. The US National Center for Health Statistics reports that men in various age groups suffer from heart disease at rates of 9.5% (45-54 years), 16.7% (55-64 years), 29.8% (65-74 years), and 42.1% (75 years or older) (7). As older adults experience higher rates of chronic disease, they are especially vulnerable to heart disease-related morbidity and mortality (8).…”

Effects of Electronic Cigarette Vaping on Cardiac and Vascular Function, and Post-myocardial Infarction Remodeling in Rats

“…Whether cigarette smoking or vaping affects the post-MI remodeling in a sex-dependent way remains controversial. Kaplan et al [ 3 ] exposed male and female C57BL/6 J mice (5 months old) to 3R4F cigarettes smoking for 2 weeks, followed by surgical permanent left coronary artery ligation and then 1 additional week post-MI smoking. In this study, compared to their nonsmoking counterpart, cigarette smoking significantly worsened both left and right ventricular remodeling only in males, but not in females, within 7 days of post-MI.…”

“…In addition, there have been reports of increased platelet activation, reactivity, and aggregation which have implications for heart attacks and strokes and strong associations of systemic inflammation and oxidative stress in vaping individuals (for review, see [ 1 ]). Animal studies have also provided experimental evidence that exposure to E-cig impairs cardiovascular function [ 2 , 3 ].…”