At the Democratic presidential debate in Nevada this week, Vermont Sen. Bernie Sanders drew attention to the fact that he isn't the only candidate who's had a heart procedure. Former New York Mayor Michael Bloomberg also had stents put in, 25 years ago.

Questions remain about Sanders' health, as he leads the pack in national polling months after he suffered a minor heart attack.

Medical ethicist Arthur Caplan joined Boston Public Radio on Friday to discuss the issue.

"Should we have more transparency? Well yes, nobody's ever actually released their records. Even Bernie only had his personal physician say he's in good shape. He never released records," said Caplan.

Sanders released doctor's notes after his heart attack, and said he would release fuller records, but this week reversed that statement and said he was not planning on releasing full records. No other candidate in the race has released full records, either.

Caplan said there is a clear way to ensure more transparency for candidates seeking top political office: Set up an independent board of physicians to conduct a thorough exam. But, there's not much precedent for presidential transparency. Franklin D. Roosevelt hid his polio, Dwight Eisenhower had a heart attack while in office, and current President Donald Trump has released his personal physician's notes after exams.

Caplan is the Drs. William F and Virginia Connolly Mitty Chair, and director of the Division of Medical Ethics at NYU Langone Medical Center. He’s also the co-host of the everyday ethics podcast.