Malaria infection is associated with increased risk of heart failure

Malaria infection is linked with a 30% raised risk of heart failure, according to a small study presented today at ESC Congress 2019 together with the World Congress of Cardiology.

The mosquito-borne infection affects more than 219 million people worldwide each year, according to 2018 statistics from the World Health Organization (WHO).

"We have seen an increase in the incidence of malaria cases and what is intriguing is we have seen the same increase in cardiovascular disease in the same regions," said first author Dr. Philip Brainin, a postdoctoral research fellow at Herlev-Gentofte University Hospital, Denmark. "Even though we have taken preventive measures to decrease the malaria numbers it remains a major burden."

The researchers used Danish nationwide registries to identify patients with a history of malaria infection between January 1994 and January 2017. The mean age of patients in the study was 34 years old and 58% were male.

A total of 3,989 malaria cases were identified, with 40% having plasmodium falciparum, a parasite transmitted through mosquito bites that is responsible for the majority of severe malaria cases in humans.

The 11-year follow-up of patients revealed 69 cases of heart failure, which was very high as compared to the general population, and 68 cases of cardiovascular death, which was considered within normal range.

"These patients had a 30% increased likelihood of developing heart failure over the follow-up time," Dr. Brainin said. "Thirty percent is a high number, but you also have to understand that it is a relatively small study, which is a limitation. As of right now the results of this study are more hypothesis-generating for future studies."

Dr. Brainin noted that, while heart failure risk was increased for patients in the study, there was not a link to heart attack or cardiovascular death.

More research will be needed to further validate the findings, but recent studies have found that malaria could be a contributor to functional and structural changes in the myocardium, which is the muscle tissue of the heart.

Experimental studies have also shown that malaria may affect the blood pressure regulatory system causing hypertension, which is a contributor to heart failure.

Malaria can also affect vascular pathways that cause inflammation in the heart, which could lead to fibrosis and then heart failure.

"I think these findings are quite interesting not only from an epidemiological perspective but also from the medical perspective," he added. "If malaria is potentially linked to cardiac disease it could represent a therapeutic target we could use to control and prevent cardiac disease in these regions."

Because it is too early to convert the results into clinical practice, Dr. Brainin advised that physicians should continue to focus on traditional and validated risk factors that may lead to heart failure.

According to the European Society of Cardiology (ESC), a combination of high blood pressure, diabetes, obesity, and coronary artery disease are among the most common risk factors for heart failure.

"I think, in light of these findings, there is room for much more research into a potentially overlooked complication to malaria, which could be development of cardiac disease or heart failure. And I hope that these findings will be a catalyst for future research into this field," he concluded.

Dr. Brainin's research group, in collaboration with Federal University of Acre in Brazil, will systematically investigate malaria patients and their cardiovascular status by looking at biomarkers, echocardiograms, and following malaria patients for cardiovascular events, beginning in 2020.