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Gregory Lewis, MD

Greg Lewis, MD
  • Cardiologist
    Massachusetts General Hospital
  • Jeffrey and Mary Ellen Jay Chair and Section Head of Heart Failure
    Medical Director of Heart Transplantation
  • Director, Cardiopulmonary Exercise Testing
    Massachusetts General Hospital

Associate Professor of Medicine
Harvard Medical School

Massachusetts General Hospital
Gray/Bigelow Building
55 Fruit Street
Boston, MA 02114

Dr. Lewis has a background is in biochemistry and cardiopulmonary physiology, combined with formal training in trial design, clinical investigation, and mass spectrometry-based metabolic profiling. A major objective of his current research is to understand mechanisms of exercise intolerance in patients with heart failure and to define physiologic and biochemical signatures of heart failure subphenotypes.

One area of focus has been on defining physiologic and metabolomic signatures of right ventricular-pulmonary vascular (RV-PV) interactions during exercise in heart failure. Through a unique exercise protocol that integrates hemodynamic measurements, ventriculography, gas exchange measurement, and plasma sampling he has found that the periodic breathing and kinetics of oxygen uptake and efficiency of ventilation provide complementary gas exchange signatures of RV-PV dysfunction during exercise. This physiologic data is complemented by measurements of circulating small molecules that serve as metabolomic signatures of abnormal physiologic patterns. Dr. Lewis has extended his investigation of exercise as a physiologic probe into the Framingham Heart Study where his team has derived physiologic and metabolic signatures of exercise response patterns.

A second area of focus is the periphery in heart failure, which constitutes the vasculature and skeletal muscle systems. Although these systems are outside of the heart they play a critical role in determining functional capacity in patients with heart failure.

His group reported that peripheral oxygen extraction is abnormal in patients with heart failure and preserved ejection fraction. To improve peripheral oxygen utilization the group is currently investigating iron homeostasis in heart failure and whether oral iron repletion improves exercise capacity in heart failure through an NIH-sponsored R01 with an embedded clinical trial (IRONMET-HF, PIs: Lewis and Malhotra). Dr. Lewis is also the PI of the MGH NIH U01 HeartShare Program which is conducting deep phenotyping of HFpEF.

Research Areas
Cardiac Physiology and Disease
Applied Exercise Physiology

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