Chronic kidney diseases and eventual heart failure have intricate connection: Study

Chronic kidney diseases can lead to heart disorder or even heart-issue related deaths reveals a recent study.

The recently conducted research led by Navkaranbir Bajaj, M.D., of the University of Alabama at Birmingham, has identified a pathological change that appears to link kidney disease to progressive heart disease.

This offers a potential treatment target, which could have a wide benefit because 14 per cent of the U.S. adult population has chronic kidney disease. The research is published in the journal Circulation, with Bajaj -- a UAB assistant professor in the Division of Cardiovascular Disease, Department of Medicine and Department of Radiology -- as the first author.

"I am now collaborating with other UAB researchers to figure out how we can target therapeutics to help these patients," Bajaj said.

The pathological change identified is coronary microvascular dysfunction, or CMD, say Bajaj and research colleagues at Harvard Medical School. CMD is a decreased blood flow in the small blood vessels inside the heart muscle that provides oxygen and fuel to feed the pumping heart.

In healthy hearts, visualized postmortem, these blood vessels look like a tight filigree network that fills the heart muscle tissue. A diseased postmortem heart has lost much of this network.

In living patients, however, those small blood vessels inside the heart muscle cannot be visualized; blood flow scans of living patients visualize only the larger, exterior coronary arteries. So Bajaj and colleagues needed an indirect way to gauge CMD.

That measure is coronary flow reserve, or CFR, which Bajaj and colleagues measured via positron emission tomography. CFR is the maximum increase in blood flow through the coronary arteries above the normal resting volume.

Bajaj, a cardiologist who trained at UAB, did his advanced imaging fellowship at Brigham and Women's Hospital in Boston, before returning to UAB in 2018.

In a longitudinal study of 352 patients with chronic kidney disease, all with healthy heart function as measured by ejection fraction and none with signs of overt coronary artery disease, the researchers measured CFR and also measured signs of subclinical heart dysfunction via deformation analysis with echocardiograms.

The patients have then followed a median of 4.4 years for major adverse cardiac events. A total of 108 patients had such major events, including death and hospitalization for non-fatal heart attack or heart failure.