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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 - Cardiovascular Disease
  • Internal Medicine

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

455 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 5
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 4.9

94 Patient Comments

Reviewed on May 14, 2024

Dr. Hammer is the best!

Reviewed on May 14, 2024

Love Dr Hammer. He is so caring and professional. Listens and explains well.

Reviewed on May 7, 2024

Dr Hammer is one of the most caring doctors ever

Reviewed on May 3, 2024

Dr Hammer is outstanding!!!

Reviewed on May 1, 2024

Care provider was outstanding.

Reviewed on May 1, 2024

Dr.Hammer is so easy to work with! He has taken wonderful care of me!

Reviewed on Apr 29, 2024

I had a great visit with Dr. Hammer. Not only was he prepared and listened to my concern, but he is very well informed about the latest in care for a bypass patient with CAD. Very much appreciated the professional care that I recieved.

Reviewed on Apr 23, 2024

Dr. Hammer is an excellent doctor!

Reviewed on Apr 2, 2024

I was very pleased with how Dr. Hammer and his staff were able to schedule my visit.

Reviewed on Mar 29, 2024

My initial appt was scheduled 4 weeks after my surgery. I understand Dr hammer schedule is tight. After my follow with Dr Hammer I will be able to give a better review.

Reviewed on Mar 20, 2024

Dr. Hammer is a very caring provider with a magnificent knowledge of medicine and in other areas besides cardiology.

Reviewed on Mar 18, 2024

Dr. Hammer is a great heart doctor. I have seen him for several years and have had to have two open heart surgeries which he has planned. I wish I could thank him everyday for taking such good care of me.

Reviewed on Mar 18, 2024

First let me say that Dr Hammer is wonderful. He kept me alive twice, post elephant trunk procedures with 18 day stays in the hospital. I come from across the country every year for a post 2015 elephant trunk procedure check up. The last two years have been difficult to get scheduled. I am directed three months ahead to start my appointments. Which I do. This year the Cat scan was not scheduled. We had our appointment with Dr Hammer without the CAT so it had to be ordered and then another meeting with Dr Hammer. Adding nearly a week to my Holiday Inn expenses! I called numerous times and sent messages to the portal to get the echo scheduled ahead of time. I was told each time I was on the wait list. I arrived in Cleveland on Friday for my Monday appointment without being scheduled yet. Called two more times. Finally, I was given a last minute schedule in the basement with a student learning to do echoes. She did inquire for help. This was a very stressful experience. Last year was similar. This has been so unlike Cleveland Clinic in the past.

Reviewed on Mar 18, 2024

Dr Hammer is an awesome doctor. He has kept me alive during the two elephant trunk procedures. I was in the hospital 18 days each time with serious complications. He also follows up with me when I return home. I am so blessed to have him as my doctor.

Reviewed on Mar 8, 2024

Dr Hammer is an outstanding physician and I felt like he truly takes interest in me and my medical issue .

Reviewed on Mar 7, 2024

Dr. Hammer is the best. I guarantee your doctor hammer is the best and he breaks it down and explains it to you where you understand what he's talking about and what you're going through. He is the best

Reviewed on Feb 27, 2024

We were very pleased with dr Hammer.

Reviewed on Feb 26, 2024

Dr Hammer and his staff are absolute top shelf medical providers, and treasures. I would come from the other side of the world to see him. Thank goodness I only have to come from Florida to Cleveland Clinic Main Campus.

Reviewed on Feb 26, 2024

This is not hard. I freely recommend Dr Hammer for anyone needing cardiac care with any condition at any time.

Reviewed on Feb 19, 2024

Dr Hammer and his staff go above and beyond just their jobs they are truely amazing

Reviewed on Feb 19, 2024

I would recommend Dr Hammer to anyone he truely is one of a kind!!!!!

Reviewed on Feb 9, 2024

Excellent doctor. Gives excellent care and follow ups.

Reviewed on Feb 6, 2024

In my opinion there is no better doctor than Dr. Hammer. He cares for you as if you were family. He researches your file, thinks things through and explains thoroughly what his plan Is for your care. You couldn't hope for anything more, he Is an amazing brilliant doctor.

Reviewed on Feb 5, 2024

Dr. Hammer is an exception communicator He explained everything in detail and provided me with much information

Reviewed on Feb 5, 2024

Dr. Hammer is great, I have recommended him to other executives who have made appointments with him.

Reviewed on Jan 29, 2024

Always a pleasure to jeer with Dr Hammera very caring doctor

Reviewed on Jan 23, 2024

Always recommend Dr. Hammer for his forthrightness and knowledge and ability to communicate and careHe Is veriy impressive.

Reviewed on Jan 18, 2024

Love Dr Hammer

Reviewed on Jan 18, 2024

Dr Hammer was a caring and very professional cardiologist!

Reviewed on Jan 17, 2024

Best experience I ever had at doctors office from the receptionist to the nurse to the doctor to the echocardiogram the whole staff was awesome.

Reviewed on Jan 17, 2024

Dr Hammer is always very thorough, professional, and personable. I feel very confident with his treatment recommendations.

Reviewed on Jan 11, 2024

Dr Hammer and his staff are beyond excellent. I especially liked the fact that you got a secretary (Kevin) so you could help stretch Dr Hammer further. Dr Hammer is the best example of what Cleveland Clinic aspires to promote.

Reviewed on Jan 10, 2024

Dr Hammer is just great.

Reviewed on Dec 14, 2023

Great doctor, very helpful

Reviewed on Dec 13, 2023

Dr.Hammer is extremely thorough and professional every time we ( my husband and myself) have met with him. Thank You!!

Reviewed on Dec 8, 2023

Very impressed with Dr. Hammer's response to my situation and his pursuit of getting me the help I needed.

Reviewed on Dec 7, 2023

We love Dr Hammer. He is a God send.

Reviewed on Dec 7, 2023

Terrific experience. Dr Hammer is a rock star! So considerate abd kind

Reviewed on Dec 1, 2023

I have been battling heart disease since 1977. Dr Hammer saved my life in 1999 and has kept me alive and living to this day. He's the most competent, respectful, dedicated and caring doctor I've ever known. I literally owe him my life.

Reviewed on Nov 29, 2023

Dr. Hammer is the best!

Reviewed on Nov 29, 2023

Dr. Hammer is the best!!!

Reviewed on Nov 17, 2023

Dr Hammer provided excellent advice and explained reasons for his decisions. I look forward to seeing him again in 6 months.

Reviewed on Nov 16, 2023

Dr. Hammer is excellent. One of the very best.

Reviewed on Nov 16, 2023

Dr. Hammer is extremely knowledgeable and communicates in an easy to understand manner.

Reviewed on Nov 14, 2023

Dr. Hammer is an excellent doctor and cares very much about his patient.

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 Nov 9, 2023

All Good: I like and respect Dr 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

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