Researchers from Cincinnati Children’s presented results from three key studies at the 2011 annual meeting of the American Heart Association, held in November in Orlando.

The findings focus upon heart conditions related to Duchenne muscular dystrophy, acute kidney injury after cardiac surgery and sudden death from restrictive cardiomyopathy.

ICDs can prevent sudden death  

A study from the Heart Institute at Cincinnati Children’s reports that sudden death from restrictive cardiomyopathy (RCM) is often triggered by a slow heart rate called a heart block – and not by rapid heart rhythms as previously assumed.

The surprising finding “changes our practice,” says Richard Czosek, MD, a pediatric cardiologist at Cincinnati Children’s and senior author of the study. “The mode of death we are seeing in our population is different than previously expected.”

RCM is the least common cardiomyopathy, but it ultimately leads to heart failure. When the condition becomes serious enough, it typically requires a heart transplant.  About half of people with RCM die within two years of diagnosis. 

"We believe RCM patients diagnosed with additional conduction system disorders should be considered for implantation with ICDs (implantable cardioverter-defibrillators), which can detect both fast and slow heart rhythms allowing for prophylactic protection from both potential mechanisms for sudden death,” Czosek says.

Read the full press release.

Detecting kidney injury within hours vs. days 

Up to 40 percent of adults and children who have cardiac surgery develop acute kidney injury (AKI), often with deadly consequences. That’s partially because the traditional test, used for the past 50 years, takes days to return results.

A new study, however, shows that a panel of biomarkers can be used to detect AKI just hours after initiation of cardiopulmonary bypass – allowing physicians to begin therapy earlier than ever before.

AKI can occur as a consequence of shock, infection, trauma, medications and other procedures. Treating AKI can involve days of intensive care, dialysis treatment and sometimes kidney transplants.

“These biomarkers not only enhance the potential for appropriately timed therapy but also offer severity and prognostic information at early time points,” says Catherine Krawczeski, MD, a pediatric cardiologist at Cincinnati Children’s.

The study reviewed the cases of 220 children who went on cardiopulmonary bypass. Of these children,  27 percent suffered an acute loss of kidney function.  When AKI occurred, urine samples revealed that NGAL increased significantly at two hours post-bypass. Three other biomarkers (IL-18, L-FABP and KIM-1) rose significantly at later points.

The study marks the first time researchers have studied all four of these biomarkers in one group of patients.

“Biomarkers, especially when used in combination, like a panel, give us the strongest predictive ability – better than using just clinical data and better than just NGAL alone,” Krawczeski says.

The traditional test for kidney injury measures creatinine, a waste product found in the blood when kidneys start to fail. However, in the days it can take for the creatinine test to show proof of injury, the patient may already have lost up to 50 percent of kidney function.

The new findings build upon research led by Prasad Devarajan, MD, director of Nephrology and Hypertension at Cincinnati Children’s, who discovered that NGAL was a useful biomarker for rapidly detecting AKI.

Read the full press release.

Extending life for children with Duchenne 

Researchers from Cincinnati Children’s have found that a common, non-invasive imaging method called speckle tracking can detect early signs of heart complications in young children with Duchenne muscular dystrophy (DMD).

Currently, most doctors rely on cardiac MRI tests to detect signs of heart failure, which is the leading cause of death among DMD patients.  However, young children often cannot sit still long enough to complete MRI scans without being sedated.

Having a test that more children can tolerate could lead to quicker detection and treatment of heart problems. That’s what speckle tracking can do, says Thomas Ryan, MD, PhD, a cardiologist at Cincinnati Children’s and lead author of the study.  

Using speckle tracking, physicians can detect and measure abnormalities in the heart as a whole and in specific heart segments in patients as young as 5 years old.

“Cardiomyopathy is inevitable in patients with DMD,” Ryan says. “We’re hoping to add to their lifespan.”

Read the full press release.