The risk of developing incident heart failure is 1.5-times higher in people with nonalcoholic fatty liver disease (NAFLD) during a median follow-up of 10 years, according to a new meta-analysis.
The risk appears to increase with greater liver disease severity and was independent of age, sex, ethnicity, obesity, and the presence of diabetes, hypertension, and other common cardiovascular risk factors.
“Health care professionals should be aware that the risk of new-onset heart failure is moderately higher in patients with NAFLD,” senior author Giovanni Targher, MD, said in an interview.
“Because of the link between the two conditions, more careful surveillance of these patients will be needed,” said Dr. Targher, who is an associate professor of diabetes and endocrinology at the University of Verona (Italy). “In particular, the results of this meta-analysis highlight the need for a patient-centered, multidisciplinary, and holistic approach to manage both liver disease and cardiovascular risk in patients with NAFLD.”
The study was published online in Gut.
Risk calculations
NAFLD has become one of the most common causes of chronic liver disease worldwide (affecting up to about 30% of the world’s adults), and is expected to rise sharply in the next decade, the study authors write. The disease is linked with liver-related conditions, such as nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma, as well as complications in other organs.
Previous meta-analyses have found an association between NAFLD and a higher risk of heart failure, though the analyses included a relatively small number of studies and a relatively modest sample size, Dr. Targher and colleagues write.
Since then, several new cohort studies have examined the association, which inspired a new meta-analysis.
The research team analyzed 11 observational cohort studies with aggregate data on more than 11 million middle-aged people from different countries, including nearly 3 million with NAFLD and nearly 98,000 cases of incident heart failure over a median follow-up of 10 years.
In the studies, NAFLD was diagnosed by serum liver enzyme levels, serum biomarkers or scores, diagnostic codes, imaging techniques, or liver histology. Four studies were conducted in the United States, three were conducted in South Korea, and four were carried out in Europe, including Finland, Sweden, and the United Kingdom.
Dr. Targher and colleagues found that the presence of NAFLD was associated with a moderately higher risk of new-onset heart failure, with a pooled random-effects hazard ratio of 1.5. The risk was independent of age, sex, ethnicity, adiposity measures, diabetes, hypertension, and other typical cardiovascular risk factors.
The association between NAFLD and heart failure risk was consistent even when the comparison was stratified by study country, follow-up length, modality of heart failure diagnosis, and modality of NAFLD diagnosis.
In addition, sensitivity analyses didn’t change the results, and a funnel plot suggested that publication bias was unlikely.
“Accumulating evidence supports that NAFLD is part of a multisystem disease that adversely affects several extrahepatic organs, including the heart,” Dr. Targher said.
“NAFLD not only promotes accelerated coronary atherosclerosis but also confers a higher risk of myocardial abnormalities (cardiac remodeling and hypertrophy) and certain arrhythmias (mostly atrial fibrillation), which may precede and promote the development of new-onset heart failure over time,” he said.
Future research
Dr. Targher and colleagues also found that the risk of incident heart failure appeared to further increase with more advanced liver disease, particularly with higher levels of liver fibrosis, as assessed by noninvasive fibrosis biomarkers or histology. With only two cohort studies that examined the association, the authors judged there was insufficient data available to combine the studies into a meta-analysis.
But the observations are consistent with other recent meta-analyses that reported a significant association between the presence and severity of NAFLD and the risk of developing adverse cardiovascular outcomes, atrial fibrillation, chronic kidney disease, or other non-liver complications.
“It’s reassuring that the observations that have come from single studies hold true when you look at the totality of evidence,” Ambarish Pandey, MD, a cardiologist and assistant professor of internal medicine at the University of Texas Southwestern Medical Center, Dallas, told this news organization.
Dr. Pandey, who wasn’t involved with this study, conducted one of the recent meta-analyses that found a 1.6-times increased risk of heart failure associated with NAFLD, as well as a further increased risk with more advanced liver disease.
Now Dr. Pandey and colleagues are studying the underlying mechanisms for the link between NAFLD and heart failure risk, including cardiac structure and function, biomarkers of injury and stress, and how proportions of liver fat influence risk. Additional studies should investigate whether resolving NAFLD could reduce the risk of heart failure, he said.
“It’s really important to look for patients with NAFLD in primary care and think about cardiovascular disease in our liver patients,” he said. “Early strategies to implement the prevention of heart failure would go a long way in reducing long-term risks for these patients.”
The study authors did not declare a specific grant for this research from any funding agency in the public, commercial, or nonprofit sectors. Dr. Targher and Dr. Pandey report no relevant financial relationships.
A version of this article first appeared on Medscape.com.