First study for cancer survivors' cardiomyopathy finds dramatic effect
SAN FRANCISCO -- Cardiac resynchronization therapy (CRT) improved heart function and outcomes for patients with chemotherapy-induced cardiomyopathy, the MADIT-CHIC study showed.
Left ventricular ejection fraction (EF) improved a relative 38% over 6 months after implantation (a 10.6-percentage point absolute increase over baseline), reported Jagmeet Singh, MD, DPhil, of Massachusetts General Hospital in Boston, at the Heart Rhythm Society (HRS) meeting.
Benefits accrued similarly across subgroups by gender, age, QRS longer or shorter than 150 ms, New York Heart Association class II or III, and EF ≤25 or >25%.
Only one out of the 30 patients treated in the study didn't have a significant improvement in EF, Singh noted at an HRS press conference. Other echocardiographic characteristics also significantly improved with CRT implantation.
"We didn't look at long-term outcomes," Singh noted. "But we do know that reverse remodeling is a surrogate for long-term outcomes. So if somebody's EF improves, they go on to do much better and they have a lower level of mortality."
"I would certainly feel comfortable in using this in patients with chemotherapy-induced cardiomyopathy," he said. "Oftentimes, people tend to write them off. If you have chemo-induced cardiomyopathy, and you have some evidence of conduction defect on your EKG, you would be a great candidate for resynchronization therapy."
There's virtually no guidance available for electrical management of chemotherapy-induced cardiomyopathy, noted HRS session study discussant Kenneth Ellenbogen, MD, of Virginia Commonwealth University Medical Center in Richmond.
Despite being a small, short-term study without hard clinical endpoints, this "is the best we have," he said. No other studies have tackled CRT use for the condition.
He concluded that the data is striking in the dramatic response to CRT.
"I think we, as clinicians, we too have a high level of suspicion in cancer survivors that, in fact, they have chemotherapy-induced cardiomyopathy. It can take a decade or more for this disease entity to present itself," Ellenbogen concluded. "And for patients who have chemotherapy-induced cardiomyopathy who qualify for CRT, we can be pretty positive and optimistic when we talk to those patients about their response to CRT."
The study was a prospective, open-label look at 30 adults at 12 cardio-oncology programs. Participants had a class I or IIa indication for CRT due to clinical heart failure with systolic dysfunction, which first developed at least 6 months after exposure to chemotherapy known to cause left ventricular dysfunction (largely anthracyclines), and without any other evident cause, as assessed by a cardio-oncologist.
The cohort was mostly women (87%). Cancer history included breast, lymphoma, and sarcoma.
Cardiomyopathy that develops in close proximity to chemotherapy treatment can be reversible when treated medically, Singh noted. This cohort was an average of more than 15 years out from chemotherapy (range 18-296 months) and all were on optimal medical therapy by the time they got to CRT, so it's a different subset of patients, he pointed out.
There were no deaths during the 6 months of follow-up. One patient had a heart failure episode, but patients uniformly had NYHA class improvement.
Limitations included the small size, lack of control group, and no long-term follow-up.
The open-label, single-arm design was also a limitation, but Singh said that they didn't want to put patients through placebo if they were eligible for CRT.
Ellenbogen agreed that few in the field would argue a control group would be needed, but he suggested that getting more data through prospective registries would be warranted.
MADIT-CHIC was supported by Boston Scientific.
Singh disclosed relevant relationships from Abbott, Biotronik, Boston Scientific, Medtronic, St. Jude Medical, Microport, Back Beat, Impulse Dynamics, EBR, Toray.
Heart Rhythm Society
Source Reference: Singh JP, et al "Cardiac Resynchronization Therapy In Chemotherapy-induced Cardiomyopathy: Results Of The Multicenter Automatic Defibrillator Implantation Trial - Chemotherapy-induced Cardiomyopathy ( Madit-chic ) Study" HRS 2019; Abstract LBCT02-04.
Read the original article on Medpage Today: Chemo-Induced Heart Failure Responds to CRT