NEWARK, N.J. (AP) — A cardiologist with offices in New York and New Jersey has admitted taking part in a scheme that subjected thousands of patients to unnecessary tests and treatment and resulted in more than $19 million in bogus bills.

Authorities are calling the case the largest case of health care fraud ever by a practitioner in either state.

Dr. Jose Katz pleaded guilty Wednesday in federal court to conspiracy to commit health care fraud.

Katz founded Cardio-Med Services LLC and Comprehensive Healthcare & Medical Services.

Prosecutors say he falsely diagnosed many of his patients, including patients with ordinary private health insurance as well as Medicare and Medicaid coverage, with coronary artery disease and debilitating angina so he could treat them unnecessarily, according to a document filed with the U.S. District Court in Newark, N.J.

The $19 million damages total includes only the amounts paid by Medicare and Medicaid. Authorities did not give an estimate of the losses incurred by private insurers in the court document.

They say he also prescribed treatment in cases in which doing so subjected the patients to risk of injury or death.

Katz is scheduled to be sentenced July 23.