Home

The Giri-Nathan Cardiovascular Health Services and Policy Research Lab focuses on using a variety of existing and novel data sources in combination with statistical modeling and econometric methodologies to address questions at the intersection of three major focus areas in health policy. These efforts are undertaken in collaboration with the Leonard Davis Institute of Health Economics, an interdisciplinary program with experts from the Wharton School of Economics and the Perelman School of Medicine.

Subject Areas:

Equitable Access to Cardiovascular Therapies

We seek to understand the socioeconomic, geographic, racial, and ethnic factors associated with access to novel cardiovascular pharmacotherapies as well as therapeutic devices using novel datasets constructed from large administrative payor databases, geospatial databases and a variety of socioeconomic markers. We aim to generate a comprehensive understanding of how economic and social factors intersect to influence access to cardiovascular therapies across diverse populations.

  • Income and Geographic Disparities in in-Hospital Mortality Following Cardiovascular Procedures: Evidence From the National Inpatient Sample, 2016–2022, Health Services Research, Nathan et al., 2026

  • Delayed or forgone medical care associated with increased resource utilization and health care expenditures among patients with peripheral artery disease in the United States, Journal of Vascular Surgery, Reddy et al., 2025

  • Racial, ethnic, socioeconomic, and geographic inequities in catheter ablation for atrial fibrillation, Heart Rhythm, Nathan et al., 2026
  • Characteristics of Clinical Trial Sites for Novel Transcatheter Mitral and Tricuspid Valvular Therapies, JAMA Cardiology, Nathan et al., 2023
  • Racial, Ethnic, and Socioeconomic Disparities in Access to Transcatheter Aortic Valve Replacement Within Major Metropolitan Areas, JAMA Cardiology, Nathan et al. 2022
  • Socioeconomic and Geographic Characteristics of Hospitals Establishing Transcatheter Aortic Valve Replacement Programs, 2012-2018, Circ Cardiovasc Qual Outcomes, Nathan et al., 2021

Factors Motivating the Adoption of Cardiovascular Therapies

Our work focuses on how reimbursement policies, treatment costs, market competition, financial incentives, and organizational characteristics shape decisions to invest in and implement new drugs, devices, and procedures. Using large administrative, claims, and cost data sources together with advanced econometric methods, we aim to understand the financial drivers of innovation uptake and identify strategies to promote high-value adoption of cardiovascular therapies.

  • Economics of Emerging Transcatheter Cardiovascular Interventions, JACC, Reddy, Nathan, Giri, 2025

  • Revenues, costs, and contribution margins of major inpatient cardiovascular procedures within the Medicare population, American Heart Journal, Reddy, Nathan, et al.,  2025

  • Economic Considerations in Access to Transcatheter Aortic Valve Replacement, Circulation Cardiovascular Interventions, Reddy et al. 2022

Risk and Outcome Assessment when Utilizing Cardiovascular Therapies

We study the accuracy and utility of measuring patient-level outcomes following the use of cardiovascular therapies, as well as how these measurements can affect physician and health system decision making using administrative and registry data sources in combination with econometric and behavioral science methodologies.

  • Hospital-Level Percutaneous Coronary Intervention Performance With Simulated Risk Avoidance, Journal of the American College of Cardiology, Nathan et al., 2021
  • Variability in Reported Percutaneous Coronary Intervention Mortality Among Physicians Practicing at Multiple Sites in New York State,  JAMA Cardiology, Yang and Nathan. et al., 2021
  • Performance of Hospitals When Assessing Disease-Based Mortality Compared With Procedural Mortality for Patients With Acute Myocardial Infarction, JAMA Cardiology, Nathan et al., 2020

In collaboration with the Cardiovascular Outcomes and Quality Effectiveness Research Group (CAVOQER), our group uses large data sets, including administrative, registry and clinical trial data sources, in combination with advanced causal inference techniques to perform comparative effectiveness studies and outcome analyses of cardiovascular therapies in the following clinical areas.

Coronary Artery Disease

  • Comparison of Patients Undergoing Percutaneous Coronary Intervention in Contemporary U.S. Practice With ISCHEMIA Trial Population, JACC Cardiovascular Interventions, Chatterjee and Giri et al. 2021
  • Comparative Outcomes After Percutaneous Coronary Intervention Among Black and White Patients Treated at US Veterans Affairs Hospital, JAMA Cardiology, Kobayashi and Giri et al., 2017
  • Impact of Optimal Medical Therapy in the Dual Antiplatelet Therapy Study, Circulation, Resor, Nathan and Mauri et al.,  2016

Structural Heart Disease

  • Oral anticoagulant use in patients with atrial fibrillation and mitral valve repair, American Heart Journal, Nathan et al., 2021
  • Lack of Association Between Percutaneous Coronary Intervention and Transcatheter Aortic Valve Replacement Outcomes in New York Hospitals, Circulation Cardiovascular Interventions, Halaby and Nathan et al., 2021
  • Conscious Sedation Versus General Anesthesia for Transcatheter Aortic Valve Replacement: Insights from the National Cardiovascular Data Registry Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry, Circulation, Hyman and Giri et al., 2017

Venous Thromboembolic Disease

  • Interventional Therapies for Acute Pulmonary Embolism: Current Status and Principles for the Development of Novel Evidence: A Scientific Statement From the American Heart Association, Circulation, Giri et al.,2019
  • Trends in catheter-directed thrombolysis and systemic thrombolysis for the treatment of pulmonary embolism, American Heart Journal, Adusumalli, Giri and Groeneveld et al.,  2019
  • Thrombolysis for pulmonary embolism and risk of all-cause mortality, major bleeding, and intracranial hemorrhage: a meta-analysis, JAMA, Chatterjee and Giri et al., 2014

Reno-vascular Hypertension

  • Patient-Level Pooled Analysis of Ultrasound Renal Denervation in the Sham-Controlled RADIANCE II, RADIANCE-HTN SOLO, and RADIANCE-HTN TRIO Trials,  JAMA Cardiology, Kirtane and Kobayashi et al., 2023

Peripheral Arterial Disease

  • Geographic and Socioeconomic Disparities in Major Lower Extremity Amputation Rates in Metropolitan Areas, Journal of the American Heart Association, Fanaroff, Nathan, Giri et al., 2021
  • Proximal versus distal embolic protection for carotid artery stenting: a national cardiovascular data registry analysis, JACC Cardiovascular Interventions, Giri et al., 2015
  • Comparative effectiveness of commonly used devices for carotid artery stenting: an NCDR Analysis (National Cardiovascular Data Registry), JACC Cardiovascular Interventions, Giri et al., 2014