Ioannis Mastoris, MD, MPH

Patient Feedback

4.92967 average rating from 182 reviews

• Dr Mastoris was caring and thoughtful in his time with me. He asked pertinent questions about my functioning. I felt taken care of.

  2026-08-22

• The Doctors of heard failure & cardiac transplantations is very nice, his team and nurses team is very good too. I have not any questions. I wish they are continuing to take my heart and body, I'm willing to do my best for me living longer, and for the doctors team and MGH get more experience on cardiac transplantation, and save more and more patients get new live. Thank you very much.

  2026-08-04

• Dr Mastoris is an absolutely phenomenal physician. I met others in the community who share this opinion

  2026-08-03

• He was kind, professional, and spent an extensive amount of time with me talking about my medical history, which he knew well, and suggested treatments and answering my questions. I felt very fortunate to have been matched with him for my care and look forward to continuing to work with him on my serious chronic health issues.

  2026-08-03

• I have been very happy with him and would recommend him to others.

  2026-08-03

• very good visit

  2026-08-02

• Professional and helpful

  2026-07-21

• It was a very friendly, informative, and efficient visit.

  2026-07-22

• Dr. Mastoris is excellent - extremely knowledgeable and professional. Grateful for his counsel and advice !

  2026-07-18

• Very good.

  2026-07-15

• It was a pleasant experience

  2026-07-17

• Dr Mastoris is top notch. Has always been prepared, helpful, and clearly interested in his patient's wellbeing.

  2026-07-15

• Excellent care team!!! I am lucky to be a patient! They saved my life in so many ways!!

  2026-07-15

• Dr Mastoris is an excellent doctor. Very knowledgeable and kind .

  2026-07-15

• My Dr. is the best. I am so impressed with all the people at MGH. The respect and care given to patients is the best I have ever seen. It is true what people say, MGH is Mans Greatest Hospital. Thank you for making me better.

  2026-07-14

• Excellent

  2026-07-11

• Provider was excellent very courtious.

  2026-07-08

• Yeah, Dr. Mastoris, I mean, what can you say about him that hasn't already been said? He's awesome in a word. He's knowledgeable. He's definitely one of the best in the business. And, you know, he does, he treats you with respect. He knows what's going on. He carefully reviews your, you know, your chart. I feel totally, I mean, given that I'm a heart failure patient, I'm very, very confident when I see Dr. Mastoris. I like the guy. He's personable and he's darn good at what he does.

  2026-07-08

• He put much effort into helping me understand the complexities involved in my diagnostic picture. He identified his intention to only use treatments and medications that would offer an improved quality of life for me. Created a comfortable environment for me to express my concerns and ask questions.

  2026-07-04

• I think this is the best checkup I've had with the doctor because I had many questions and he answered them for me. We went over everything and I felt comfortable and good with my report. I just think he's fantastic.

  2026-07-02

• Very kind and informative and understanding.

  2026-07-02

• Dr. Mastoris is the BEST. I love his personality and philosophy regarding my delicate health issues.He is very thorough and professional in regard to my questions and does not rush through the appointment. He is fully aware of the specifics of my health history. [redacted]

  2026-06-13

• I was very satisfied with my appointment with Dr Mastoris and did not feel rushed and he answered all of my questions.

  2026-06-10

• Dr. Mastoris always is very thorough and patient with all my questions. He explains things so I can understand them

  2026-06-06

• Yes, I'm definitely very satisfied with my nurses and provider.

  2026-05-25

• The provider was informed of my history and suggested plans of action regarding continuing difficulties with my recovery. As well as noting difficulties with various medications

  2026-05-23

• Hi, my name is [redacted] and it was a wonderful visit with him. He was so easy to talk to. He understood my problems. He understood everything and he explained everything to me in a manner that I understood. He was a wonderful doctor and I would recommend him to all of my family and all of my friends. The Mass General is the best and we're so lucky to have it.

  2026-05-23

• He provides excellent care and makes me feel comfortable with his recommendations.

  2026-05-19

• Great staff

  2026-05-20

• Very happy with him. He does a great job and I feel as if he genuinely cares.

  2026-05-04

• He is exceptional. I feel blessed that he is my doctor. I only wish he were more available.

  2026-05-04

• It was excellent. The doctor is fantastic

  2026-05-01

• - listens to you - actually makes eye contact - knowledgeable - respects your time - very personable

  2026-04-26

• Excellent first appointment

  2026-04-17

• My cardiologist as well as MGH is best hospital in the world !

  2026-04-15

• Outstanding!

  2026-04-13

• The doctor and everyone in the office were extremely helpful, professional, and it's a pleasure to have been there. Thank you.

  2026-04-10

• Very professional

  2026-04-07

• The doctor was excellent. He was very thorough. He listened to everything I had to say. He looked at the report in front of me and was able to explain to me what was going on as I showed him EKG strips for my phone. He took it in and he was very willing to listen to everything I had to say. The nursing staff was great. Lori in the head office was incredible. It was very impressive of how well they worked and how good of treatment they were able to provide me.

  2026-04-06

• Everything was very good, had long conversations with provider who was very informed.

  2026-04-05

• This was my first time seeing this provider. He was amazing! I have a very complex condition. It was refreshing to have a provider who actually listened. He gave me plenty of time. He explained everything clearly and I left feeling very well taken care of.

  2026-04-01

• Another very productive visit.

  2026-04-01

• Very professional and very well informed about my health needs

  2026-04-01

• Comfortable, competent and professional experience

  2026-03-31

• The doctor was knowledgeable and kind. Although my father is [redacted] years old and in poor health, the doctor did not treat him as if he is too old or too sick to help. The doctor had a detailed plan ready to discuss to try to improve my father's health. He spent a good amount of time with us, explained things well and offered to answer any questions.

  2026-03-28

• Dr. Mastoris spent a great deal of time with me to answer all of my questions and to discuss concerns. Hw also stated that he was going to speak with the SCAD unit because he really felt I needed to be able to do some exercises and he was knowledgeable enough that he felt the "old" information wasn't accurate. The next day he had an answer for me in my portal and when I asked one more question he got back to me that day.

  2026-03-26

• I feel blessed to have Dr Mastoris as my new cardio md and hope to have many more healthy years ahead of me

  2026-03-24

• Everything was great ?

  2026-03-26

• It is always a pleasure to meet with him!!!!!

  2026-03-23

• Dr. Mastoris gave me the time to discuss my medical issues. He is very knowledgeable and very helpful.

  2026-03-18

• This was my first visit with this Dr. He was easy to talk with, he listened to me and heard my concerns. I felt that he actually cared.

  2026-03-17

• Dr Mastoris is very thorough, he explains my condition in a way that is easy to understand. He describes the direction my treatment is going and what next steps look like.

  2026-03-15

• I have been going to MGH for my heart for 34 years. This last appointment was one of the best in terms of efficiency. Everyone I dealt with (over ten people) was courteous, positive, knowledgeable and even fun! I am so glad to live within an hour (2 1/2 during traffic:) of MGH. Thank You to the entire team! [redacted]

  2026-03-09

• My Doctors are always willing to help if I reach out. I have the most respect and 100% confidence in the ability to take care of me.

  2026-02-19

• My husband and I were so happy to finally meet with a doctor that truly cares and takes the time to listen to our concerns.

  2026-02-08

• Dr. Mastoris is very professional, very good knowledge about heart problems and does an excellent job.

  2026-02-06

• I love Doctors Mastoris . He is fantastic and explains everything so good

  2026-02-05

• Dr. Mastoris was great.

  2026-02-04

• Excellent visit, covered all the important details, was very knowledgeable and showed empathy.

  2026-02-06

• The medical staff has been nothing but amazing. They listen to me and don't dismiss my concerns.

  2026-02-04

• They are very good

  2026-01-29

• Good appointment

  2026-01-26

• I couldn't be more satisfied with each and every appointment that I have had at MGB We are blessed to have the quality of care . Thank you, [redacted]

  2025-12-12

• I met Dr. Mastoris when I was hospitalized for heart failure. I am very impressed with him and happy that he is my physician now. He is thorough, listened to his patients, compassionate and spends time. He is an expert and I am very fortunate to have him. He has an immediate plan to help me and is expediting my treatment. [redacted]

  2025-12-12

• Dr. Matsoris is a treasure: personable, interested in more than raw medical Information; interested in treating the patient and not just the issue at hand.

  2025-11-27

• Dr Mastoris took his time and listened, explained and showed interest in my situation All great

  2025-11-27

• The Dr. I had seen was very interested in my thoughts and concerns

  2025-11-20

• I had a very good experience with the doctor and he did not rush my appointment

  2025-11-13

• My mom and I were very pleased with the Doctor and his willingness to not rush us but answer questions. He also explained things very clearly so my mom and I could understand. It was a very good experience.

  2025-11-08

• Dr Mastoris was extremely knowledgeable about me and my history. I feel extremely grateful to have him for my doctor. He is very thorough and takes his time to explain everything to me. [redacted]

  2025-11-06

• Dr. Mastoris was very thoughtful, informative, and warm-hearted. I felt very comfortable and cared for and well informed about the whole situation. Thank you very much.

  2025-11-07

• they are great

  2025-10-31

• Dr.mastoris very helpful in me understanding my heart problems and what has to be done and what to expect. Dr. Was very clear and easy to understand what I had to do. My experience at mass general was excellent.

  2025-10-28

• Always very professional and I appreciate their care.

  2025-10-31