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Department Cardiovascular Medicine
Primary Location Cleveland Clinic Main Campus
Type of Doctor Adults Only
Languages English
Surgeon No
Cleveland Clinic Main Campus
Primary Location

Cleveland Clinic Main Campus

Specialties & Treatments

Treatment & Services

  • Aorta Center
  • Cardiology
  • Cardiovascular Medicine
  • Cardiovascular Medicine Department
  • Clinical Cardiology Section
  • General Cardiology
  • Perioperative Cardiac Management
View all 7 Treatment & Services +


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About Donald Hammer, MD

Dr. Donald Hammer is Director of Cardiology Surgical Services and a staff cardiologist in the Section of Clinical Cardiology, the Robert and Suzanne Tomsich Department of Cardiovascular Medicine, at the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute. He is board certified in internal medicine and cardiology. Dr. Hammer's specialty interests are ischemic heart disease and perioperative cardiac management.

Dr. Hammer graduated summa cum laude from Case Western Reserve University (Phi Beta Kappa) with an undergraduate degree in chemistry. He received his medical degree from The Ohio State University College of Medicine, in Columbus, Ohio, where he was inducted in the Alpha Omega Alpha honor society. He completed his clinical internship and residency in internal medicine at The Ohio State University Hospitals, where he went on to receive a fellowship in cardiology.

Dr. Hammer served 10 years in the United States Naval Corps and retired as a Lieutenant Commander, U.S. Naval Medical Corps. He has had multiple academic appointments, which include Clinical Instructor in Internal Medicine at The Ohio State University Hospitals; Director of Education, Internal Medicine at the Naval Regional Medical Center at Camp Pendleton, CA; Assistant Clinical Professor of Medicine and Associate Medical Director of the Cardiac Transplantation Program at The Ohio State University Hospitals; Education Coordinator for Cardiology at Wright State University in Dayton, OH, where he was also Director of the Cardiology Fellowship Training Program; Director of the Echocardiography Laboratory and Chairman of the Cardiology Research Panel at Good Samaritan Hospital in Dayton, among others. In 1998, Dr. Hammer was appointed to the Cleveland Clinic Foundation as Director of Cardiology Surgical Services.

Dr. Hammer has long been involved in clinical studies on his specialty interests and heart related issues. His post basic research endeavors included high-energy phosphate analysis in dilated cardiomyopathy and CHF. He currently is the principal investigator on a retrospective comparison of second and third generation beta blockers and post-operative atrial fibrillation prophylaxis, and is a co-investigator on the safety and efficacy in low molecular weight heparin in selected patients post open heart surgery. Dr. Hammer has participated in many other clinical trials including the QUIET STUDY and in the GUSTO trials.

He has presented his research findings and addressed his specialty interests at many national conferences and symposia. He is the author or co-author of articles related to his work in leading publications, including Circulation, Heart, and the New England Journal of Medicine, to name a few. In addition, he has co-authored a chapter on endogenous inotrope in a medical textbook on Cardiotonic Drugs.

Dr. Hammer is Fellow in the American College of Cardiology and a member of the American Medical Association, the American Society of Echocardiography and the Medical Society of Northeastern Ohio.

Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - The Ohio State University Hospitals
Columbus, OH USA

Residency - The Ohio State University Hospitals
Internal Medicine
Columbus, OH USA

Internship - The Ohio State University Hospitals
Internal Medicine
Columbus, OH USA

Medical Education - The Ohio State University College of Medicine and Public Health
Columbus, OH USA

Undergraduate - Case Western Reserve University School of Medicine
Cleveland, OH USA


  • Internal Medicine
  • Internal Medicine - Cardiovascular Disease

Specialty Interests

General cardiology, heart disease, aorta disease, perioperative cardiac management

Research & Publications

Research & Publications

See publications for Donald Hammer, MD.

(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

Industry Relationships

Industry Relationships

Cleveland Clinic physicians and scientists may collaborate with the pharmaceutical or medical device industries to help develop medical breakthroughs or provide medical expertise or education. Cleveland Clinic strives to make scientific advances that will benefit patient care and support outside relationships that promise public benefit. In order for the discoveries of Cleveland Clinic physicians' and scientists' laboratories and investigations to benefit the public, these discoveries must be commercialized in partnership with industry. As experts in their fields, Cleveland Clinic physicians and scientists are often sought after by industry to consult, provide expertise and education.

To assure professional and commercial integrity in such matters, Cleveland Clinic maintains a program that reviews these collaborations and, when appropriate, puts measures in place to minimize bias that may result from ties to industry. Cleveland Clinic publicly discloses the names of companies when (i) its physicians/scientists receive $5,000 or more per year (or, in rare cases, equity or stock options) for speaking and consulting, (ii) its physicians/scientists serve as a fiduciary, (iii) its physicians/scientists receive or have the right to receive royalties or (iv) its physicians/ scientists hold any equity interest for the physician's/scientist's role as inventor, discoverer, developer, founder or consultant.* In publicly disclosing this information, Cleveland Clinic tries to provide information as accurately as possible about its physicians' and scientists' connections with industry.

As of 3/20/2022, Dr. Hammer has reported no financial relationship with industry that is applicable to this listing. In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.

Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.

* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.

Patient Satisfaction Reviews

281 Patient Satisfaction Reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our nationally-recognized Press Ganey Patient Satisfaction Survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Responses are measured on a scale of 1 to 5 with 5 being the best score.

The comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Cleveland Clinic.

Overall Star Ratings
4.9 out of 5
Explains 4.9
Listens 4.6
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 4.9

58 Patient Comments

Reviewed on Jun 13, 2022

Dr Hammer is an excellent Dr I am very happy to be treated by him very grateful

Reviewed on Jun 10, 2022

Both the doctor and his assistant took their time and were very thorough and professional. Dr. Hammer seemed genuinely determined to find the cause of my problem.

Reviewed on May 27, 2022

I am lucky to have Dr Hammer as my cardiologist He explained a new treatment for me .He reviewed the literature in excellent way.I am a physician.I asked him lot of questions regarding the study leading to approval of the new medicine.He answered my questions in very professional way.Dr Hammer is a valuable asset to Cleveland Clinic in my opinion.

Reviewed on May 23, 2022

Mostly clear explanations and concerns were provided during the visit. The doctor seemed to understand that if he listens to the patient he may get an understanding of how the patient is hearing/understanding the subject matter. The doctor spoke and did take time to listen quite intently.

Reviewed on May 10, 2022

Like Dr Hammer,his Nurse assistant

Reviewed on May 10, 2022

Staff is very helpful. I have a feeling they do all they can to accommodate my needs. The problem is that Dr. Hammer, is very popular in his time is valuable. Not withstanding the foregoing, I am pleased to have Dr. Hammer, as my cardiologist

Reviewed on May 9, 2022

Dr, Hammer is a very good doctor and a caring individual

Reviewed on May 2, 2022

My husband and I are very thankful to have Dr. Hammer as our heart doctor. He is very knowledgeable, kind, and caring with both of us. He always listened if we have a concern.

Reviewed on Apr 27, 2022

Dr Hammer's resident was VERY thorough and went through my chart and history for quite a while. I appreciated his attention to detail.

Reviewed on Apr 21, 2022

Dr Hammer is great the people who run the clinic VERY BAD

Reviewed on Apr 18, 2022

Very pleased with the service overal.Ver happy to have Dr.Hammer as my Doctor.

Reviewed on Apr 7, 2022

Very pleased with Dr Hammer, have already recommended him to others.

Reviewed on Apr 4, 2022

Dr Hammer, Is great. Explained my condition clearly. And answered all of my questions. Highly recommend him and the Cleveland Clinic.

Reviewed on Apr 4, 2022

Dr Hammer, is Great Explained everything and answered all my questions

Reviewed on Mar 7, 2022

Dr Hammer is a wonderful Dr. He takes time to listen and explain things.

Reviewed on Feb 24, 2022

I feel that the doctor actually listens when I explain the issues I am having.

Reviewed on Feb 22, 2022

Dr Hammer and his resident, Dr Ravin, were both extremely professional and courteous.

Reviewed on Feb 15, 2022

Dr Hammer is compassionate and caring. I have great respect for him and trust his medical knowledge.

Reviewed on Jan 20, 2022

Always a easy and good check up with Dr.

Reviewed on Jan 18, 2022

Very appreciative of this provider!

Reviewed on Dec 27, 2021

Doctor Hammer is outstanding. I have every confidence in his treatment of me.

Reviewed on Dec 16, 2021

Dr Hammer is great, very kind and compassionate, also professional. He took the time to evaluate me and answer my questions, and is also quite personable. He puts people at ease.

Reviewed on Dec 13, 2021

Dr. Hammer and his team are outstanding!! So happy I have fantastic care.

Reviewed on Dec 9, 2021

Very happy with Dr.Hammer and his staff.

Reviewed on Dec 9, 2021

Dr. Hammer is great. So glad he is my cardiologist.

Reviewed on Dec 7, 2021

Dr Hammer provides service like Dr Holiday in Gunsmoke home town style

Reviewed on Dec 7, 2021

Always a n excellent experience as Dr Hammer is understanding, through, and reassuring.

Reviewed on Dec 2, 2021

Dr. Hammer is fantastic. Patient, knowledgeable, informative etc. I have the utmost confidence ion the care I receive from him. Also saw an Intern and nurse both of which were excellent.

Reviewed on Dec 1, 2021

Dr. Hammer is exceptional. I'm incredibly fortunate to have him as my cardiologist.

Reviewed on Nov 30, 2021

I have been under Dr. Hammer's care for well over 15 years and am grateful to have one of the best doctors in the business.. I appreciate that during an appointment he gives me whatever time is needed and doesnt appear rushed and he makes me part of the decision making team.

Reviewed on Nov 29, 2021

Dr. Hammer was very knowledgeable and explained everything thoroughly.

Reviewed on Nov 19, 2021

I know I'm in very good hands with Dr.Hammer.

Reviewed on Nov 15, 2021

Excellent physician. Caring. Thoughtful and concerned

Reviewed on Nov 3, 2021

Dr.Hammer is the "BEST"

Reviewed on Nov 2, 2021

I had an outstanding experience. The Doctor and intern made clear there was a lot of work to do and a long journey ahead for me. They assured me we would take one step at a time and they would be with me along the way to explore all options. They were frank but assuring and I left feeling positive and confident.

Reviewed on Oct 29, 2021

Dr Hammer's staff was very responsive and helpful in following up with an order after the appointment

Reviewed on Oct 28, 2021

Dr.Hammer has been my cardiologist since 2008 always goes over my lab and test results so I can understand them and his opinion of how to improve the bad and to hold steady of the good. Any questions or concerns I have he explains before I leave my appointment.

Reviewed on Oct 28, 2021

Satisfied with the care of my physician

Reviewed on Oct 21, 2021

I respect Dr Hammer and value his medical advice

Reviewed on Oct 21, 2021

Asked when he came in, why was I there. After being referred by another Cleveland Dr. He would have know my case.

Reviewed on Oct 19, 2021

Dr Hammer was excellent as always!

Reviewed on Sep 30, 2021

Dr. Hammer was terrific

Reviewed on Sep 22, 2021

Dr. Hammer and staff deserves an A+

Reviewed on Sep 20, 2021

Dr. Hammer is a primary example of why Cleveland clinic is #1 in the world. He took care of me in 2015 and 2016 for an elephant trunk procedure during two 18 day stays. He kept me alive. I moved to Florida. He monitored my BP via phone ever Sunday evening and adjusted my meds. He is the best doctor I have ever had. That is why is I travel 2000 miles to see him.

Reviewed on Sep 17, 2021

Dr Hammer is excellent

Reviewed on Sep 13, 2021

Dr Donald Hammer is phenomenal with his patients! He has an manner in which he is easy to talk to, listens intently,and explain any problems I was having! He is very knowledgeable in his field, in my case very intent on determining my multiple diagnoses and will order the tests that will try to determine what is going on within my body causing the problems. On 9/13/21 Dr Hammer's resident was awesome! She was professional, made me feel I was being listened to, took a thorough assessment of me, made appropriate suggestions and relayed to Dr Hammer her findings. My visit with Dr Hammer, as always, was detailed, accurate, explained thoroughly and professionally his thoughts and tests he wanted ordered and why. Very cognizant that we were out of state, from South Carolina. My visit was extremely on a different course since I exhibited different signs and symptoms at this visit than before. Always asked if I understood what and why he was telling me the what he suggested. Phenomenal physician!

Reviewed on Sep 9, 2021

Dr. Hammer is very caring and helped me through a difficult time.

Reviewed on Sep 8, 2021

Dr Hammer has always been most professional.

Reviewed on Sep 8, 2021

Dr. Hammer is very caring, thorough and clearly knows my case and me.

Reviewed on Sep 3, 2021

Dr Hammer is excellent. I told him what I thought was wrong. He said, "I believe you." That was really important to me. We found exactly what I told him I thought was wrong on the catheterization. His staff promptly replied to my messages in MyChart. That is also important because I have never had any major angioplasty or anything like this.

Reviewed on Sep 1, 2021

Dr Hammer is a great doctor, he takes time to talk and explain everything !

Reviewed on Aug 25, 2021

Dr Hammer went beyond the norm.

Reviewed on Aug 25, 2021

Dr . Hammer is exceptional ! I am thrilled that my husband's care is in his capable hands . His staff is very efficient also

Reviewed on Aug 23, 2021

Dr Hammer is wonderful. Have thought that from the very beginning !

Reviewed on Aug 5, 2021

Dr Hammer is the world's best. We are very blessed & thankful for him. We brag about him everywhere.

Reviewed on Aug 3, 2021

My appointment had to be changed because the scheduler did not follow the requested tests by my doctor.

Reviewed on Aug 3, 2021

Dr. Hammer is excellent, very friendly, clear, patient, knowledgeable, and frank. I feel fortunate to have gim as my doctor and recommend him to others without hesitation. Just a geat doctor.

Reviewed on Jul 21, 2021

Dr Hammer is a very caring doctor and is interested in my condition and sincere about improving my health.

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