Improving the Response to CRT Nonresponders

Cardiac resynchronization therapy (CRT) has been a godsend for individuals with advanced heart failure, but as many as one-third of patients fail to respond. Those patients are the target population of a CRT optimization clinic recently launched under the leadership of electrophysiologist John Rickard, MD, MPH, Director of Cleveland Clinic’s CRT Program.

John Rickard, MD, MPH

In the absence of a thorough multidisciplinary assessment, these patients are at increased risk for poor exercise tolerance, repeat hospitalizations and early death. Dr. Rickard explains that the clinic is designed to “troubleshoot the care of the sickest patients” with a collaborative, multidisciplinary approach that uses a comprehensive algorithm-driven evaluation to systematically identify possible reasons for nonresponse to CRT.

‘Leave no stone unturned’

“Private practices generally do not have the bandwidth and size to support this sort of program,” he says, adding that, in community settings, communication between the relevant subspecialties is often difficult and care tends to be fragmented. In contrast, at Cleveland Clinic’s CRT Optimization Clinic, electrophysiologists work in close collaboration with other cardiologists and imaging specialists as a team.

“Our goal is not to reinvent the wheel but to leave no stone unturned,” Dr. Rickard explains, noting that the new clinic is one of only a handful of its kind across the U.S.

He recommends that all patients who receive a CRT device get re-evaluated within six to nine months afterward to ensure optimal functionality. Patients who stand to benefit from the clinic include those who have had no clinical or echocardiographic improvement following device implantation or have improved only transiently. An algorithm-driven exam considers a slew of factors that may contribute to CRT nonresponse, with the aim of optimizing response and longer-term outcomes. Results of the algorithm-based exam are shared with the patient and referring physician to adjust management accordingly.

The clinic’s protocol at a glance

The CRT optimization clinic, held twice a month, is fully integrated with Cleveland Clinic’s heart failure disease management program and accessible to patients of any referring cardiologist. Appropriate patients include those who experience persistent advanced heart failure symptoms (New York Heart Association functional class III or IV) and/or continuation or lack of reversal of adverse cardiac remodeling following CRT device implantation.

“The first clinic visit takes about two hours,” Dr. Rickard notes. To evaluate biventricular pacing, the patient has an electrocardiogram with and without CRT pacing. Device positioning of the left ventricular lead is checked on chest radiographs. Laboratory tests (standard electrolyte and renal panel, complete blood count) are performed to determine if anemia or renal dysfunction is involved.

“We perform a comprehensive device interrogation,” Dr. Rickard explains. “That includes assessment of battery status, lead impedances and thresholds, heart rate and activity histograms, percentage of atrial and ventricular pacing, and the presence of atrial and ventricular tachyarrhythmia.” Echocardiographic measures are averaged from at least three consecutive cycles, in conformance with American Society of Echocardiography guidelines.

Multidisciplinary recommendations — often to address multiple factors

A dedicated multidisciplinary team — an electrophysiologist, a heart failure specialist and a cardiac imaging physician — reviews results of the comprehensive exam together and makes joint recommendations on how to improve CRT for the patient, which are shared with the patient and referring cardiologist for input and buy-in.

“The most frequent reasons for nonresponse include poor left ventricular lead position, a poor substrate for biventricular pacing, and suboptimal atrioventricular timing, but our recommendations are often not mutually exclusive,” says Dr. Rickard. He notes that the team often finds they can help with one or more of the following measures:

• Repositioning the left ventricular lead
• Altering atrioventricular device programming
• Treating arrhythmias either medically or invasively
• Adding and up-titrating medical therapy
• Changing advice on diet and fluid intake

What follows the initial visit

All patients typically present for an initial two-hour visit at the clinic. If a major intervention is required (e.g., reoperation to move a lead), the recommendation is discussed with the referring physician and a plan is formulated. Typically, one extra visit is needed if a major intervention takes place. If only minor device changes are needed or no significant interventions are possible, patients are followed by their referring cardiologist with Cleveland Clinic’s CRT Optimization Clinic acting in a consultative role.

“If we can help these sickest heart failure patients have a better quality of life — with fewer hospital readmissions — as well as live longer, that will be an important contribution,” Dr. Rickard says.

To refer a patient to Cleveland Clinic’s CRT Optimization Clinic, call 216.444.3254.