Coronary Microvascular Dysfunction and Cardiovascular Risk in Obese Patients
Navkaranbir S Bajaj1, Michael T Osborne2, Ankur Gupta1
1Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Journal of the American College of Cardiology
|August 11, 2018
Summary
Coronary microvascular dysfunction (CMD) is a significant cardiovascular risk in obese patients, independent of body mass index (BMI). Impaired coronary flow reserve (CFR) better predicts adverse events than BMI alone.
Area of Science:
- Cardiology
- Obesity Medicine
- Vascular Biology
Background:
- Obesity presents challenges in cardiovascular risk assessment beyond Body Mass Index (BMI).
- Coronary Microvascular Dysfunction (CMD), characterized by impaired Coronary Flow Reserve (CFR) without obstructive coronary artery disease, is an emerging cardiovascular risk indicator.
- Identifying reliable risk discriminators is crucial for obese patients, particularly those considering bariatric surgery.
Purpose of the Study:
- To investigate the interrelationship between obesity, CMD, and adverse cardiovascular outcomes.
- To determine if CFR is a better predictor of adverse events in obese patients compared to BMI.
Main Methods:
- Cardiac stress positron emission tomography was used to assess coronary perfusion in 827 patients evaluated for coronary artery disease.
- Patients with normal perfusion were followed for a median of 5.6 years to record adverse events like death, myocardial infarction, or heart failure.
- Statistical analyses, including adjusted models, were performed to assess the association between BMI, CFR, and cardiovascular events.
Main Results:
- An inverse J-shaped relationship was found between BMI and CFR, with CFR decreasing linearly as BMI increased in obese individuals.
- Impaired CFR, but not BMI, was independently associated with adverse cardiovascular events.
- Patients with impaired CFR exhibited a significantly higher adjusted rate of adverse events compared to those with normal CFR, even in the absence of current bariatric surgery indications.
Conclusions:
- CMD is independently associated with elevated BMI and adverse outcomes in patients referred for cardiac testing.
- CFR serves as a more effective discriminator of cardiovascular risk in obese patients than BMI and traditional risk factors.
- Measuring CFR could enhance the clinical management of obese patients by providing a more accurate risk assessment beyond current markers.
Related Concept Videos
01:21Drug Dosing: Obese Patients
268
In the United States, obesity is a prominent concern. It is linked to heightened mortality rates due to increased occurrences of conditions such as hypertension, atherosclerosis, coronary artery disease, and diabetes compared to nonobese individuals. A patient is classified as obese if their actual body weight surpasses the ideal or desirable body weight by 20%, based on Metropolitan Life Insurance Company data. Ideal body weights consider average weights and heights for males and females...
268
01:25Pharmacokinetics in Obese Patients: Drug Absorption and Distribution
286
Obesity significantly alters the pharmacokinetic processes of drug absorption and distribution, presenting unique challenges in medical treatment. The increased fat tissue and decreased lean muscle in obese individuals can significantly affect how drugs are absorbed into the body and distributed across different tissues. This alteration can lead to variances in the effectiveness and safety of medications, necessitating adjustments in dosing or drug selection for obese patients.One notable...
286
01:20Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion
191
Drug metabolism, a critical process in the liver, involves two primary phases: Phase I reactions and Phase II conjugation. Obesity introduces significant alterations in this metabolic process, primarily due to fatty infiltration of the liver, leading to conditions such as nonalcoholic fatty liver disease (NAFLD). This condition can modify the activities of both Phase I and II enzymes, impacting how drugs are metabolized in obese patients.Phase I metabolism sees variable effects across...
191
01:24Obesity
1.4K
The Body Mass Index (BMI) is a numerical value derived from a person's weight and height, used to categorize individuals into weight ranges. It is calculated using the formula: weight in kilograms divided by height in meters squared. Obesity is a health condition characterized by excessive accumulation of adipose tissue that poses health risks, often diagnosed with a BMI ≥ 30. This excess fat storage occurs when surplus dietary calories are converted into triglycerides and stored in...
1.4K
01:12Relative Risk
2.2K
Relative risk (RR) is a statistical measure commonly used in epidemiology to compare the likelihood of a particular event occurring between two groups. This metric is important for evaluating the relationship between exposure to a specific risk factor and the probability of a particular outcome. It plays a crucial role in medical research, public health studies, and risk assessment. Relative risk quantifies how much more (or less) likely an event is to occur in an exposed group compared to an...
2.2K
01:14Overview of the Cardiovascular System
12.0K
The cardiovascular system is a vital transportation system in the body. It comprises the heart and blood vessels and facilitates the exchange of gases, nutrients, and waste products.
Heart
The heart is the central pump of the cardiovascular system that circulates blood throughout the body. It comprises two atria receiving the blood and two ventricles pumping blood out of the heart. Their rhythmic contractions, called heartbeats, ensure that blood flow remains continuous.
Blood Vessels
Blood...
Heart
The heart is the central pump of the cardiovascular system that circulates blood throughout the body. It comprises two atria receiving the blood and two ventricles pumping blood out of the heart. Their rhythmic contractions, called heartbeats, ensure that blood flow remains continuous.
Blood Vessels
Blood...
12.0K