Reversing A Global Trend

In 2016, Dr. Margaret “Molly” McNairy witnessed what she called an “epidemiologic transition” in Haiti.

“We discovered that the most serious health risk to the general population in the capital city of Port-au-Prince was no longer HIV, malaria or TB, as it had been in previous years,” says Dr. McNairy, who since 2014 had made monthly visits to Haiti in support of her work to prevent the spread of HIV/AIDS. Instead, an increasing number of patients were presenting to local clinics with symptoms of cardiovascular disease, especially early-onset high blood pressure and premature heart disease.

Haiti was not the only place where this kind of shift was noted in a resource-constrained setting. Dr. Daniel Fitzgerald, director of Weill Cornell Medicine’s Center for Global Health and the B.H. Kean Professor in Tropical Medicine, observed a similar trend while working at the Weill Cornell Bugando Program in Tanzania, where he also noticed a rise in heart failure and strokes in people in their 30s and 40s.

“Haiti, like the majority of low-income countries, was a data desert in terms of heart disease,” explains Dr. McNairy. In order to make sense of and try to reverse this global trend, Dr. McNairy, along with fellow core center faculty Dr. Jean Pape and Dr. Vanessa Rouzier, instituted the Haiti Cardiovascular Disease Cohort. Supported by the National Heart, Lung, and Blood Institute and GHESKIO, a research facility and public health clinic in Port-au-Prince led by Dr. Pape, the Howard and Carol Holtzmann Professor in Clinical Medicine, the study aims to chart and evaluate modifiable cardiovascular risk factors and disease in 3,000 Haitian adults ages 18-30 to identify drivers that can be targeted for prevention.

After following study participants for several years, Dr. McNairy and her colleagues found that heart disease presents differently in resource-poor countries like Haiti. “Unlike higher-income countries, where ischemic heart disease is caused by clogged arteries from too much fat and sugar,” explains Dr. McNairy, “the cause in Haiti is under-recognized and untreated high blood pressure, affecting one in three adults, including many under 30.”

They also found that risk factors contributing to disease are dissimilar from factors in western countries. The Haiti CVD Cohort study showed that pollution — most commonly elevated blood lead levels — and nutrition challenges stemming from food insecurity are among the modifiable causes.

In response, Dr. McNairy and her colleagues are collaborating with local community and public health experts to personalize interventions to fit patient needs. For instance, community health workers visited patients with uncontrolled hypertension in their homes and took blood pressure readings, provided health education and delivered medications. Blood pressure control increased from 0% to 72% after six months.

“We’re improving blood pressure control by leveraging social networks of these communities,” says Dr. McNairy. “The mission of our study is to use data to save lives, and the silver lining is that cardiovascular disease is a preventable disease.”