Cardiac CRN

Background

Over 25% of all deaths in the US are attributed to cardiovascular disease3. Cardiovascular interventions are the most common procedures worldwide and often involve the use of implantable devices. Among these procedures, the treatment of aortic stenosis can be performed using surgical or transcatheter interventions. In the US, more than a million such procedures have been captured in the Society of Thoracic Surgeons (STS) and Transcatheter Valve Therapy (TVT) registries over the past decade. With the recent growth of transcatheter aortic valve replacement (TAVR), it is important to compare the long-term safety and effectiveness of transcatheter vs. surgical valve implants.

FDA approved the first TAVR device in 2011 for patients who were considered at extremely high risk or inoperable through traditional surgeries 4. Since then TAVR has been approved for patients considered to be at high, intermediate, and low risk for surgery4. With the expansion of TAVR to younger and lower risk patients, there are increasing needs to investigate the long-term durability of TAVR valves4. Under this scientific premise, the conversation to establish a Cardiac CRN and engage stakeholders from multiple areas began. The envisioned Cardiac CRN would bring together registries and claims data enabling comparative studies with longitudinal follow-ups. As a step toward building the infrastructure and foundation for the CRN, claims-based studies are conducted to investigate relevant topics. In addition, international efforts for collaboration have been initiated to conduct multi-country or multi-region studies.

Objectives

The current objective of the Cardiac CRN is to investigate the short and long-term safety and effectiveness of cardiac valve devices utilizing existing data infrastructures and/or a combination of them. These research aims will provide the evidence needed for clinical and regulatory decision making and timely issuance of societal treatment guidelines supported by data. A secondary objective of CRN is evaluation of percutaneous mechanical cardiac support devices.

Partnership Structure

Cardiac CRN is a collaborative effort that involves partners from private and public agencies such as the FDA, CMS, and New York State Department of Health; academic partners include Weill Cornell Medicine and University of California San Francisco (UCSF) and industry collaborators include Abiomed. Cardiac CRN leads include John Laschinger (Gore Vascular), Joseph Bavaria (University of Pennsylvania), Ralph Brindis (American College of Cardiology), Vinod Thourani (Piedmont Heart Institute).

Existing agreements
Memorandums of understanding (MOU) have been signed between the MDEpiNet Coordinating Center and CRN leadership to join the CRN COP.

Data Infrastructure

Patient population
Cardiac CRN initiative focuses on patients who are 18 years or older with clinical conditions such as aortic valve replacement and cardiac support services such as percutaneous mechanical cardiac support, balloon pumps, and ECMO.

Data sources
The Cardiac CRN data sources include EHRs, administrative claims, and registry data.

Current Projects and Plans

Cardiac CRN’s current research projects include valve replacement safety and outcome studies, mechanical cardiac support devices investigating patient morbidities, and coronary bypass grafting studies using the STS registry.

Valve replacement safety and volume outcomes: This study used national and regional claims databases to evaluate the impact of annual and 5-year cumulative volume of surgeons on the short-term outcomes after aortic valve replacement and mitral valve replacement. This study utilized New York State discharge data between 2000 and 2016 and determined mortality, major events, and 30-day readmission following valve replacement.

Another study is focusing on the impact of physician characteristics on the short-term outcome following TAVR procedures using New York State discharge data with linkage to physician data. The New York State discharge data is also used to examine the use pattern of other cardiac procedures, including percutaneous coronary intervention, pacemaker and defibrillator implantation, among patients undergoing TAVR procedures, compared with those undergoing Surgical Aortic Valve Replacement (SAVR) procedures.

Assessment of trends of mechanical cardiac support devices: This study aims to determine the use of mechanical cardiac support devices and patient morbidities. This study uses Nationwide Inpatient Sample and assesses the recent trends of device adoption as well as patient morbidity profiles and healthcare costs related to the devices. A collaborative initiative was formed with Abiomed, Inc. to assess the feasibility of linking clinical study data and CMS claims data. The investigated cohort was a clinical trial of mechanical cardiac support devices use among percutaneous coronary interventions’ patients. The pilot effort will investigate the linkage efficiency between clinical study data and claims database.

Coronary bypass grafting study (CABG): This study compares the incidence of deep sternal wound infections following CABG procedures using bilateral internal thoracic arteries (BITA) graft and non-BITA graft using the STS adult cardiac surgery database. Subgroup analysis is also planned among patients who are obese, patients with diabetes, and patients with chronic lung disease.

Methodological projects: Currently, Cardiac CRN plans to engage stakeholders to firmly establish the CRN, continuously conduct TAVR/SAVR comparative long-term studies, and develop data linkage and statistical methodologies for CRN studies and/or claims and registry-based studies.

On an international level, methodological work is planned to harmonize data analyses using administrative data. Regional databases from New York State and Ontario will be used to evaluate use of TAVR and short-term outcomes after the procedure. New York State and Ontario regional data will also help evaluate adoption of TAVR and short-term outcomes after TAVR procedures in these two regions.