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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 10/6/2023, 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

389 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 4.9
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 5

76 Patient Comments

Reviewed on Nov 10, 2023

We have been patients of Dr. Hammer since 2014 and now four other family members see Dr. Hammer in addition to two of our friends. Dr. Hammer is a wonderful doctor and he is the reason we tolerate the rudeness by the registration at labs etc

Reviewed on Nov 10, 2023

We will continue to recommend Dr. Donald Hammer

Reviewed on Oct 30, 2023

Dr Hammer was very patient and kind. He went above and beyond taking time to sit with us after hours to discuss the different possibilities of what might be going on with Alex.

Reviewed on Oct 26, 2023

I have an annual checkup with Dr Hammer, but your system does not allow appointments to be booked a year in advance. I was instructed to call on the first of each month to inquire if appointments were being taken for the month I needed (August 2023). After being told for several months to call back next month', I was finally able to book an appointment - but not until October 2023. My recommendation would be to allow established patients to be able to book their annual checkup 12 months in advance.

Reviewed on Oct 26, 2023

Dr. Hammer is exceptional in all aspects of patient care!

Reviewed on Oct 25, 2023

Dr. Hammer is outstanding. Very thorough. Tremendous expertise. Very caring.

Reviewed on Oct 19, 2023

Dr Hammer is outstanding. He put me at ease and I was very stressed about the procedure.

Reviewed on Oct 18, 2023

Very good visit easy kind Doctor was very concerned about my progress before my visit ended He asked if I had any questions He took care of

Reviewed on Oct 17, 2023

Dr. Hammer is an amazing doctor that is very attentive to my concerns and care.

Reviewed on Oct 17, 2023

Dr Hammer is EXCELLENT!

Reviewed on Oct 13, 2023

Dr Hammer is excellent

Reviewed on Sep 28, 2023

Dr. Hammer took more time explaining my issues, potential solutions and personal care for me in one day than my prior cardiologist has in 10 plus years. Dr. Hammer took the extra time to speak with my surgeon prior to that appointment and also made time in his day to see me again after consulting with the surgeon. I am very fortunate to be under Dr. Hammers care and Cleveland is lucky to have him.

Reviewed on Sep 22, 2023

Dr. Hammer is the best, would never never go to any other cardiologist. Started seeing him in my 50's now in my 80's. Always concerned about my condition like talking to a friend rather than a doctor. Always leave there feeling he cares. There is no other Dr. Hammer.

Reviewed on Sep 22, 2023

Being in the hospital numerous times, I received excellent care from the wonderful nurses & Dr Hammer's team in giving me the care I needed to bring me back to health with all my heart issues.

Reviewed on Sep 20, 2023

Dr Hammer is always prompt & professional. He makes you feel at ease and handles his patients as if they are family. Thank you Dr Hammer!

Reviewed on Sep 14, 2023

Dr. Hammer and his interns are always thorough and excellent.

Reviewed on Sep 14, 2023

Excellent care from Dr. Hammer, complete confidence in him.

Reviewed on Aug 28, 2023

It is easy to communicate with Dr Hammer through his assistant Jackie. Also, he calls me directly when he feels we need to talk.

Reviewed on Aug 28, 2023

Dr. Hammer has always spent time explaining everything to me in detail, often using illustrations to ensure I understand. It certainly helps understand.

Reviewed on Aug 25, 2023

Dr Hammer has been great over the years. I feel he is a major reason I'm still KICKING.

Reviewed on Aug 17, 2023

Dr. Hammer answered so many of our questions. Took his time with us and helped us understand and was very personable!

Reviewed on Aug 17, 2023

Dr. Hammer is absolutely fantastic!

Reviewed on Aug 7, 2023

Dr Hammer is excellent doctor

Reviewed on Aug 7, 2023

Dr Hammer has been an absolutely amazing doctor. We really appreciate the time he spends with us and his clarity when explaining things A+

Reviewed on Aug 1, 2023

Dr hammer is a wonderful physician.

Reviewed on Jul 31, 2023

Dr. Hammer is by far one of the best doctors I have seen in years. It definitely take years of experience to get where he is. God bless him!

Reviewed on Jul 28, 2023

Dr. Hammer showed sincere concern for me as a patient.

Reviewed on Jul 14, 2023

Dr. Hammer is excellent and very thorough. He gave me a complete explanation of my health situation. Very appreciative of this.

Reviewed on Jul 12, 2023

Dr. Hammer was awesome

Reviewed on Jun 30, 2023

We love Dr Hammer. He is wonderful.

Reviewed on Jun 28, 2023

*Dr. Hammer is great!

Reviewed on Jun 27, 2023

Dr Hammer is a terrific, knowledgeable and caring doctor!

Reviewed on Jun 26, 2023

My expectations for Dr. Hammer are always high and he always exceeds them. I have recommended him to several other patients and will continue to do so. The

Reviewed on Jun 26, 2023

My experience with Dr. Hammer was excellent.He explained everything very clearly and listened to all my concerns. I feel he is extremely conscientious and really cares about me. He's the best!

Reviewed on Jun 19, 2023

Dr Hammer is excellent as is his staff.

Reviewed on Jun 15, 2023

Unfortunately the person who scheduled my appointment put it too close to the time of my tests. This made me over an hour late for appointment with Dr. Hammer.

Reviewed on Jun 12, 2023

I feel fortunate to have Dr Hammer as my Cardiologist.

Reviewed on Jun 8, 2023

Dr.Hammer is an excellent doctor, I know I'm receiving the best care.

Reviewed on Jun 2, 2023

Dr. Hammer is GREAT!

Reviewed on Jun 2, 2023

We had trouble with Zoom on my end. Dr Hammer then called on IPhone and completed the meeting FaceTime. He did a great job and the meeting went well

Reviewed on May 31, 2023

My appointment with Dr. Donald Hammer was just perfect. Great experience.

Reviewed on May 31, 2023

Dr. Hammer is always quite thorough with me during my appointment and he explains everything to me in detail.

Reviewed on May 31, 2023

Everything regardng my appointment with Dr. Donald Hammer went like "Clock Worth."

Reviewed on May 24, 2023

Dr. Hammer and everyone else were great. Dr. Hammer was very patient and clear in answering all my questions and explaining things.

Reviewed on May 24, 2023

As mentioned previously Dr. Hammer is a terrific communicator and explanation. In a pacient non condescending manner.

Reviewed on May 23, 2023

I came to Dr.Hammer for a second opinion on my cardiology problem. We had an excellent discussion about my issue. Dr. Hammer suggested plans for short term and long term. I left his office feeling confident with my new cardiologist. I was also very pleased that there was a team approach within his examine room to assist with the initial patient interview process and later to assist Dr. Hammer with the typing input of Dr. Hammer's time spent with me, his patient.

Reviewed on May 23, 2023

Dr. Hammer has an excellent team!! It certainly is a team approach. This type of organization builds the patient's confidence within all departments. The EKG staff was very organized and efficient at the appointment I had right before Dr. Hammer's appointment.

Reviewed on May 23, 2023

Love Dr. Hammer

Reviewed on Apr 24, 2023

Dr. Hammer took his time and explained in great detail my history and diagnosis. Did not feel rushed.

Reviewed on Apr 18, 2023

Dr. Hammer is the best

Reviewed on Apr 17, 2023

It's doctors like Hammer and Bilitko that we come out of state, to be seen.

Reviewed on Mar 9, 2023

*Dr. Hammer and his team are just outstanding in everything they do.

Reviewed on Mar 5, 2023

*Dr. Hammer was very good in explaining why the delay in doing heart scan with the dye. *Dr. Hammer is very positive & professional & I am glad I had him for the load _____.

Reviewed on Mar 1, 2023

The provider is first class and extraordinarily important in meeting my health care concerns.

Reviewed on Feb 22, 2023

Dr. Hammer was very caring and even followed up with a phone call with further details.

Reviewed on Feb 21, 2023

My experience with the doctor was very good educational experience He asked me questions explained his findings I understood what He explained to me He asked me if I had any questions I said no and thanked him and how much I appreciated him

Reviewed on Feb 21, 2023

Excellent Doctor Takes the time to talk about me as to how I'm feeling very patient very professional and helpful

Reviewed on Feb 15, 2023

You should have an excellent (#6) rating for Dr. Hammer!!

Reviewed on Feb 10, 2023

For over a decade, Dr. Hammer has provided me with excellent care. He is compassionate about his patients and has always explained medical issues and procedures so I and my wife fully understand what my condition and issues are. I fully trust Dr. Hammer and his decisions and recommendations.

Reviewed on Feb 8, 2023

We were unable to connect for the video, however, Dr. Hammer called me immediately and we conducted a very thorough discussion.

Reviewed on Feb 7, 2023

Dr Hammer is excellent in his concern ,care and explanation of the problems!

Reviewed on Feb 6, 2023

Dr. Hammer listens and explains things very well.I feel he is very dedicated, and really cares about his patients.

Reviewed on Feb 6, 2023

Dr. Hammer took the time to explain well

Reviewed on Feb 3, 2023

Dr. Donald Hammer is one of the finest physicians I have ever had or met. First, his clinical knowledge is outstanding. But he also knows how to transfer that knowledge into a top of the line care plan for the patient. I would highly recommend him to anyone! His care is well worth the 3-4 hour drive from my home here in Ohio!

Reviewed on Feb 2, 2023

Dr Hammer is wonderful

Reviewed on Jan 26, 2023

Appointments are always an issue. Hard to get, even if the doc wants it.

Reviewed on Jan 23, 2023

Our records from our home hospital did not reach Cleveland or they were lost- so will find out more about the condition later- Dr. Hammer took tests of his own and will call me.

Reviewed on Jan 19, 2023

I was completely and satisified with every aspect of my Cardiology appointment with Dr. Donald Hammer.

Reviewed on Jan 17, 2023


Reviewed on Jan 10, 2023

Over and above. Was very lucky to have Dr. Hammer as a physician.

Reviewed on Jan 10, 2023

Excellent very nice Love Doctor DHammer very patient and I like He explained things to me

Reviewed on Jan 10, 2023

Very Kind Knowledgeable Doctor

Reviewed on Nov 29, 2022

Dr hammer is good

Reviewed on Nov 29, 2022

I have the utmost respect for Dr Hammer and feel very comfortable under his care and direction. He explains thoroughly and listens to our questions and concerns. Dr Hammer makes me feel like I am the focus of his attention and I never feel that he is in a rush. He has great follow up and is accessible.

Reviewed on Nov 29, 2022

I am glad I made the decision to have this life altering treatment at the Clinic and continue to have that decision reinforced as I continue my follow up care. It is also a very positive experience that I was able to coordinate labs, testing and re-hab in the Akron area while under the care of Dr Hammer (this convenience is greatly appreciated).

Reviewed on Nov 18, 2022

What can you say having the BEST in Cardiology?The only thing that can make it better? GET DR. HAMMER THE SUPPORT HE NEEDS!! HE WANTS TO FOCUS ON HIS PATIENTS AND RESEARCH! Not deal with every administrative aspect that a proper support team should provide. It is not fair to him and can have eventual consequences.

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