Predicting Cardiovascular Events in Low-risk Patients
For male patients increased left-ventricular mass (LVM) was predictive of a cardiovascular event, while LVM-to-volume ratio was predictive in female patients
Cardiovascular disease (CVD) is a major cause of death in people worldwide. CVD is characterized by structural alterations in the size and shape of the myocardium over the course of the disease, termed left ventricular (LV) remodeling. Because LV remodeling occurs early in the development of CVD, it is a well-established marker for cardiovascular risk stratification and for monitoring a patient’s response to therapy.
The gold standard for evaluating this marker is cardiac MRI. However, such imaging is typically only used on those patients considered to be at a high risk for a cardiovascular event.
But what about lower risk patients?
“Patients with lower risk for cardiovascular issues tend not to receive preventative therapies, but many will go on to suffer from heart attacks, heart failure or cardiovascular death,” said Jonathan Weir-McCall, PhD, a radiologist and clinical senior lecturer at Cambridge Cardiovascular in the U.K.
Dr. Weir-McCall recently co-authored a Radiology study on the long-term prognosis of left ventricular remodeling in those at low to intermediate cardiovascular risk.
“Our hypothesis was that an increased left ventricular mass (LVM), which is associated with an increased risk for cardiovascular events, as detected with MRI helps predict future cardiovascular events in low-risk patients,” he explained.
The study also looked at whether the same risk markers exist for men and women, or whether different markers should be used for each sex. “There is a known significant difference in left ventricular structure between the sexes,” Dr. Weir-McCall added. “Understanding these differences is critical for accurately defining risk in men and women equally and modifying the underlying mechanisms in a targeted, individualized manner.”
Different Risk In Men And Women
The study looked at 1,475 patients lacking established risk factors like diabetes or hypertension and having a low cardiovascular risk (i.e., 10-year risk of coronary heart disease of less than 20% as predicted by the Adult Treatment Panel III algorithm). Participants underwent baseline cardiovascular MRI with measurements of LVM and volumes and were then followed up for a median of 10 years.
Based on this evaluation, researchers concluded that the left ventricular mass was the best marker of risk in men, while the ratio of the left ventricular mass-to-volume ratio was the best predictor in women. In those with the most severe LV remodeling (based on each of these two metrics), the risk of cardiovascular events was >10%, which is the current threshold for starting preventative therapies.
“These findings highlight that risk in men and women must be considered separately, with cardiovascular MRI identifying a new cohort of patients who may benefit from earlier intervention to prevent future events,” Dr. Weir-McCall said.
More specifically, the findings provide a detailed evaluation of different drivers of LV hypertrophy and LV remodeling in both sexes. For instance, while the relationship between elevated blood pressure and LV hypertrophy is well known, the study extends this observation to participants without overt hypertension.
“LV hypertrophy is usually associated with multiple factors, such as age, blood pressure, and diabetes, and results in increased stiffness of the LV myocardium,” said Jérôme Garot, MD, PhD, professor in the cardiovascular imaging section at the Institut Cardiovasculaire Paris Sud, Massay, France, who co-authored a commentary on the study for Radiology. “However, this study found that LVM was associated with age, blood pressure, smoking status and cholesterol in women and with age and blood pressure in men.”
Dr. Garot noted that this finding has important implications, suggesting that women with elevated LVM or LVM-to-volume ratio could benefit most from targeted statin therapy, while men could benefit most from aggressive blood pressure control for LVM regression.
More Research Needed
While these findings pave the way towards more individualized management and treatment of cardiovascular disease, additional research is warranted.
“The physiologic pathways leading to LVM progression in volunteers without known CVD remain incompletely elucidated, and the results of this study taught us that these relationships will need to be studied in sex-specific populations,” Dr. Garot concluded.
“What we need now are prospective trials to test whether earlier targeted intervention in those with more severe left ventricular remodeling leads to a reduction in subsequent cardiovascular events,” Dr. Weir-McCall said.
For More Information
Access the Radiology study, “Sex-specific Associations between Left Ventricular Remodeling at MRI and Long-term Cardiovascular Risk,” and the commentary, “The Clinical Weight of Left Ventricular Mass and Shape.”
Read previous RSNA News on cardiac imaging:
- Research Identifies Imaging Measurements and Serum Biomarkers Associated with Cardiac Strain and Myocardial Injury
- Low-income Country Cardiac Imaging Procedures Remain Down Post-COVID
- Researchers Develop New Coronary Risk Score for Women