HCA Holdings Inc. said Monday the Justice Department wants information about heart procedures performed at some of its locations.

The New York Times published a report late Monday citing evidence that some HCA hospitals were performing unnecessary, and sometimes dangerous, heart procedures with the aim of driving up profits for the hospital chain.

HCA said the civil division of the U.S. Attorney's office in Miami has asked for information about reviews that assess the medical necessity of some interventional cardiology services.

It also said the civil division of the Justice Department has contacted HCA as part of a national review of whether charges to the federal government for implantable cardio-defibrillators met government criteria.

The company said the Justice Department indicated it will review billing and medical records at 95 HCA hospitals. HCA runs 163 hospitals and 110 free-standing surgery centers.

HCA spokesman Ed Fishbough declined to elaborate on the information requests, which were detailed in a quarterly report filed by the company with the Securities and Exchange Commission.

The company posted a four-page letter on the home page of its website, telling visitors on Monday that the Times "appears to be making broad points concerning patient care provided at our company's affiliated hospitals."

The letter, which is unsigned and not directed to a specific audience, comes with two pages of charts detailing totals for certain procedures performed at HCA locations. It was posted before the Times published its story.

Among points addressed in the letter, HCA notes that decisions on the necessity of some heart procedures are "the subject of much debate in the cardiology community."

The Times cited internal emails, confidential memos and transcripts from hearings that raise questions about whether procedures such as cardiac catheterization and stent implants were being done unnecessarily at HCA hospitals.

HCA also said Monday its second-quarter net income jumped 71 percent in a performance that topped analyst expectations.

The company earned $391 million, or 85 cents per share, in the quarter that ended June 30. That compares to net income of $229 million, or 43 cents per share, in last year's quarter. Revenue climbed 14 percent to $9.15 billion.

Analysts surveyed by FactSet expected, on average, earnings of 78 cents per share on $8.03 billion in revenue.

For the full year, HCA also reaffirmed its forecast for adjusted earnings of $3.57 to $3.77 per share on $32 billion to $33 billion in revenue.

Analysts expect, on average, earnings of $3.58 per share on $32.65 billion in revenue.

Company shares fell $1.05, or 4 percent, to close at $25.55 Monday after falling as low as $23.91 earlier in the session. Its shares are down 19 percent since peaking for the year at $31.39 on June 29.