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 +


Is Cleveland Clinic Part of Your Insurance?

Review a list of accepted insurance plans for our Northeast Ohio locations or learn more about purchasing a contracted managed care plan.

View All Plans

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 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
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 6/7/2020, 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

285 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

86 Patient Comments

Reviewed on Aug 19, 2020

dr hammer was very informative

Reviewed on Aug 19, 2020

Have been consulting with Dr. Hammer for 12 years now. I feel blessed and fortunate to have him as my Doctor. Without question, he is first class in all aspects of his profession.

Reviewed on Aug 17, 2020

My 3 Cardiology appointments were scheduled by Dr Hammers office. They assumed they were doing me a favor to make all three on the same day... As I live 5 minutes drive from the clinic, two separate days would have been far better!By the time I saw Dr Hammer st the end ofthe day, he apologized for being over an hour late. I was ok with that, until he reported having just spent 90 min. with each of two new patients. (The appointments are scheduled for 30 - 40 min.) I realized Dr Hammer was on hisway to a departmental meeting, as he hastilydescribed my own aortic stenosis & scribbled some drawings.I am also a first time patient. Perhaps my appointment should have been rescheduled? I have a PhD in Medieval History- no preparation for a rapid fire run through of gradients , et alia.I am believing this is a confidential response!If not, I will be off to UH, where my seconddaughter is an Attending physician in Critical care ( There was no response requested for the Echocardiogram... Ten days later, I stillhave bruises on and below my left breast.)Final point: YOU MUST notify patients that only one door is open at the fountain. As I parked at Carnegie/ E. 100th, I ended up jogging 3/4 mile to avoid being late for the first appointment. Dr Hammer later joked that would "do" as a stand in for stress test.

Reviewed on Aug 17, 2020

No bad experience Dr. Hammer has been my doctor for 12 yrs. Thank you Dr. Hammer for choosing cardiologist as your profession.

Reviewed on Aug 12, 2020

we Love Dr Hammer!!!

Reviewed on Aug 11, 2020

Dr Hammer provided excellent care.

Reviewed on Aug 11, 2020

Dr. Hammer always takes time to answer any questions or concerns. He really seems to care about his patients health and well being.

Reviewed on Aug 10, 2020

I like this method as it places great focus on the discussion between the doctor and patient

Reviewed on Aug 10, 2020

very professional service. I am very happy to have Dr. Hammer and his staff providing my cardiac care.

Reviewed on Aug 6, 2020

Dr. Hammer and his staff are always very attentive. Neither the assistant,nor Dr. Hammer ever make me feel like I am being rushed through. Dr. Hammer always takes whatever time necessary to be sure all my questions are answered and I understand test results.

Reviewed on Aug 4, 2020

Excellent. Dr. Hammer is so good to us. Great doctor for my mother.

Reviewed on Aug 4, 2020

Nothing will ever replace seeing Dr. Hammer in person. But this was 2nd best.

Reviewed on Aug 3, 2020

Doctor Hammer was very honest and I felt like I was his only patient. he is very professional. thank you.

Reviewed on Jul 30, 2020

Dr. Hammer is always supportive, concerned, informative, and patient. It's clear that he cares about his patients and he explains things well.

Reviewed on Jul 29, 2020

After my initial contact with Dr. Rosellis office by phone, communications between myself and the Cleveland Clinic, requests for my medical records and tests which I promptly provided, and subsequent scheduling of appointments and tests at the Clinic went very well.

Reviewed on Jul 29, 2020

My morning appointment with a Resident cardiologist, and then with Dr. Hammer (prior to the CT scan and Echocardiogram tests I had) went well. The Resident cardiologist, looking at my CT scan from January at Union Hospital, and echocardiogram performed at Aultman Hospital in February, measured my aneurysm at 4.8 to 4.9. This was larger than the 4.5 to 4.6 diameter as measured by Dr. D'Agostino at Aultman, from the same tests. I didn't get a very good explanation of the different aneurysm size measurements by Aultman and Cleveland Clinic physicians from the same tests. My visit with Dr. Rosellis was very short, as he was called to surgery after only 5-6 minutes with me. I didn't get to ask him a single question regarding my aneurysm condition, limits to physical activity, details of surgery to repair the aneurysm, how long would be in the hospital following surgery, how long to recover, and so on. This is in no way a criticism of Dr. Roselli - if and when I need to have my aneurysm surgically repaired, I would certainly want Dr. Roselli and his surgical team to perform the operation. I am just expressing my disappointment in the brevity of my consultation with him. I fully understand that he was unexpectedly called away in urgency.

Reviewed on Jul 15, 2020

I deeply appreciate Dr. Hammer's concern for me and my well-being.

Reviewed on Jul 2, 2020

Very happy and grateful to get an appointment with Dr Hammer

Reviewed on Jul 1, 2020

Very impressed with Dr. Hammer's response time. He works in an exceptionally busy environment and still got back to me the same day. All staff members were friendly and demonstrated much concern for my welfare.

Reviewed on Jun 30, 2020

Dr. Hammer was very patient and took a lot of time helping me to relax. He did a great job of making sure that I understood everything about my care and risks. I woulD highly recommended Dr. Hammer. He is very kind.

Reviewed on Jun 30, 2020

excellent doctor

Reviewed on Jun 29, 2020

Dr. Hammer has always treated me with respect and empathy as a patient. He explains everything in detail and in a manner which is understandable. He is a true professional who has great knowledge and experience. I'd highly recommend him.

Reviewed on Jun 29, 2020

Excellent as always concerning Dr Hammer.

Reviewed on Jun 26, 2020

Dr Hammer is great. He explains everything so well that you understand your problem. His bedside manner is great.

Reviewed on Jun 25, 2020

The ease of getting appointments is much harder now due to COVID-19 rescheduling and how popular Dr. Hammer is as an excellent cardiologist.

Reviewed on Jun 25, 2020

Dr. Hammer is an excellent listener and offers personal insight for proposed treatments.

Reviewed on Jun 24, 2020

Dr Hammer is a very through physician - professional !!

Reviewed on Jun 23, 2020

Dr. Hammer always goes above and beyond.We have several friends and family members who now have him as their cardiologist as a result of our recommendation.

Reviewed on Jun 23, 2020

always a professional and informative visit with Dr. Hammer. Thank You!

Reviewed on Jun 10, 2020

Always get optimal care from Dr. Hammer.

Reviewed on Jun 9, 2020

Dr Hammer and his team always do an excellent job. I wouldn't expect anything else.

Reviewed on Jun 8, 2020

Dr. Hammer is well informed, very patient, compassionate, and goes above and beyond to care for his patients.

Reviewed on Jun 3, 2020

Dr. Hammer is very knowledgeable, concerned, caring, and thorough in the care of his patients. He has been a great hearth doctor for both my husband and me.

Reviewed on Jun 2, 2020

Dr Hammer and his staff has always offered me detailed information about the state of my health in an easy to understand language and clearing any possible doubts. that's why he's still my dr of choice after 17 years when it comes to my cardiovascular health

Reviewed on Jun 2, 2020

Dr Hammer made me feel like I was the only patient he had and presented all the information I needed to keep healthy.

Reviewed on Jun 1, 2020

I have the utmost respect for Dr. Hammer. On each visit, even if he is behind in his schedule, he takes all the time necessary to deal with my concerns. He seems to respect my opinions and answers all of my questions. His knowledge and bedside manner are very comforting. He is a great cardiologist and a compassionate person.

Reviewed on Jun 1, 2020

We have always have exceptional appointments with Dr. Hammer. Ditto with Charlie his nurse. We have often (not most recent) had to wait in the lobby to see him. I suspect due to the fact that he doesn't rush his appointments. And he listens. He already has reviewed the chart by the time we get into the room so he is prepared as best he can be. At times we have been instructed by him to call his cell phone at home to report bp's. He also called us when we were on vacation (he was too) because we hadn't communicated lately with the clinic and he feared the worst. What doctor does that anymore? We are grateful to Dr. Hammer and truly believe Russell is alive today because of his exceptional care at the clinic.

Reviewed on May 6, 2020

Dr. Hammer is the BEST !

Reviewed on May 5, 2020

I had an excellent connection with the physician. He explained and incorporated me in all the decisions. I was very pleased with the outcome and with the direction set for my visit next year.

Reviewed on May 4, 2020

A compassionate, knowledgeable, and caring provider.

Reviewed on May 1, 2020

Dr. Hammer was wonderful!

Reviewed on May 1, 2020

Dr Hammer is very professional, highly knowledgeable, compassionate physician and we have and will continue to recommend him to family and friends!

Reviewed on May 1, 2020

Dr. Hammer spent an hour with me and made me feel a lot better about the status of my recovery frommitral valve repair

Reviewed on Apr 29, 2020

If there was an excellent rating...that's what I would give Dr. Hammer.

Reviewed on Apr 16, 2020

though this was a virtual visit, I liked the doctor very much for his insight into my health problem, his cautious decisions, and his humor which put me at ease. knowing of his reputation, I was happy with his humanity.

Reviewed on Apr 14, 2020

Dr.Hammar is great physician.He has been the best doctor I have ever had

Reviewed on Mar 11, 2020

Dr Hammer was very thorough with me during my visit

Reviewed on Mar 10, 2020

Dr. Hammer was attentive and explained all of his opinions and conclusions completely. Good follow-up after the appointment.

Reviewed on Mar 5, 2020

dr Hammer was excellent!

Reviewed on Mar 3, 2020

Dr. Hammer was very professional and put me ease for my upcoming surgery.

Reviewed on Mar 2, 2020

Very impressed by the coordination of care between the physicians I met with to provide me with an overall plan.

Reviewed on Feb 27, 2020

Had to wait about a Month but Dr Hammand is worth the wait.

Reviewed on Feb 26, 2020

I did a lot of research before selecting Dr Hammer, and I have not been disappointed in my choice. Very competent and very caring

Reviewed on Feb 21, 2020

Wow! My family has great respect for Dr. Hammer. He is a physician who truly cares about helping. He takes time to explain thoroughly his feelings of what is happening and also what the best Treatment. I appreciated that he made my care and treatment his priority. Dr. Hammer even used his out of office time to share his findings with me. Thank you, Dr. Hammer. You are the best!

Reviewed on Feb 19, 2020

Dr. Hammer was very professional and thorough in his consultation and analysis of my health condition. He instilled confidence, knowledge and experience as he advised on and diagnosed my condition.

Reviewed on Feb 11, 2020

Very pleased with the care and time given at Cleveland Clinic. Top notch provider and staff. Will recommend him to anyone in need.

Reviewed on Feb 4, 2020

I have worked with Dr. Hammer for about 25 years. He is very competent. . like a. friend.

Reviewed on Jan 29, 2020

Dr. Hammer is a very caring DR. Specifically followed up regarding treatment and medications

Reviewed on Jan 27, 2020

Dr. Donald Hammer is always very thorough with his examination of me. He always explains everything in detail and should I have any questions, he answers them without hesitation. For this, I am very appreciative. When I leave his office, I am completely happy because any questions I may have had, have been answered.

Reviewed on Jan 15, 2020

Very pleased with all doctors and their teams.

Reviewed on Dec 20, 2019

Dr Hammer does a great job. He is an excellent doctor.

Reviewed on Dec 20, 2019

Dr. Hammer was very thorough in his assessment. I appreciated his expertise and concern for my problems.

Reviewed on Dec 13, 2019

dr. Hammer is the best he is great I love doctor hammer he goes over everything with you in detail and explains it to you so you understand

Reviewed on Dec 13, 2019

like I said before the doctor Hammer is the best he is great

Reviewed on Dec 12, 2019

I got the impression Dr. Hammer was having a bad day and not on top of his game. He seemed a bit distracted going off in many directions about healthcare in general and not focused entirely on his patient. I asked for my cardiac rehab script, and he asked me to go get a chest x-ray and that he would order the script. Upon my return Charlie was unavailable and I waited another ten minutes and then left.

Reviewed on Dec 11, 2019

I had a great experience . I'm very happy with Dr. Hammer.

Reviewed on Dec 5, 2019

Dr. Donald Hammer is a. very professional doctor at the Clinic. He is knowledgeable about my issues and explains them to me so I can understand them. Cleveland Clinic is very fortunate to be him on staff.

Reviewed on Nov 22, 2019

excellent physician goes the extra mile

Reviewed on Nov 22, 2019

Dr. Hammer is phenomenal!

Reviewed on Nov 21, 2019

Have always had the best care with Dr Hammer.

Reviewed on Nov 20, 2019

dr Hammer is great

Reviewed on Nov 14, 2019

Dr. Hammer was very caring,informative and timely. He took his Time in explaining my problem in addiction . I did not feel rushed nor did I feel intimidated to ask a question.

Reviewed on Nov 14, 2019

I did not have any bad experiences at the Cleven clinic . All personell were , caring and cordial. All doctors and nurses made you feel that your health needs were going to be met and they truly cared about the outcome . The facility was extremely clean.

Reviewed on Nov 14, 2019

As always, I was very impressed with Dr. Hammer.

Reviewed on Nov 11, 2019

Dr. Hammer is great!!!

Reviewed on Oct 17, 2019

Dr. Hammer is just awesome takes time with me and is very knowledgeable. I wouldn't go anywhere else . Dr. Hammer has such a good bed side manner he is perfect. He saved my life.

Reviewed on Oct 17, 2019

Dr. Hammer so knowledgeable and has awesome bedside manner . we all love Dr. Hammer.

Reviewed on Oct 16, 2019

dr. Hammer and his staff worked hard to get all of my appointments scheduled while I was here from Northh Carolina.

Reviewed on Sep 25, 2019

this was a regular follow up appointment for my aortic valve stenosis. a student accompanyed Dr. Hammer which did not negatively affect the quality of the visit in any way.

Reviewed on Sep 25, 2019

love Dr Hammer

Reviewed on Sep 19, 2019

wonderful physician!!

Reviewed on Sep 12, 2019

superb provider

Reviewed on Sep 10, 2019

love Dr. Hammer

Reviewed on Sep 10, 2019

I did a lot of research in selecting Dr Hammer and I was very satisfied with my initial visit. He spent 45 mins with me reviewing my medical history and asking me a lot of questions. I am confident I made a good decision to have Dr Hammer as my cardiologist.

Reviewed on Sep 9, 2019

The entire staff and fellow were excellent.I will wait as long as necessary for Dr. Hammer as he is exceptional. Scheduling tends to over schedule him. but with his work ethic he takes the time necessary and beyond making certain the patient understands.

Reviewed on Sep 9, 2019

experience very good, DR Hammer is always responsive to questions and so very courteous and dear....

Related Videos Featuring Donald Hammer, MD

Related Videos Featuring Donald Hammer, MD

Back to Top