Cardiac service doubles patient capacity in just under two years

Growth in demand for cardiovascular MR services has prompted some center operators to shift attention from physician acceptance of cardiac MR to productivity issues. In a measure of CMR's maturity, centers are taking steps to address its increasing popularity.

Now approaching its third year of operation, the Nashville Cardiovascular Magnetic Resonance Institute has doubled its volume to eight cases daily. The service, based on a 1.5T dedicated cardiac scanner, grew from 53 procedures in its first month of June 2003 to 150 studies in December 2004, said medical director Dr. Dipan Shah in a plenary session at the Society for Cardiovascular Magnetic Resonance meeting in February.

The service's case mix has evolved as Heart Group, a 25-member cardiology group that owns the service, has built the business (Figure 1). At first, vascular imaging made up 65% of patient volume, and CMR accounted for 35%. After 18 months, the percentages have flipped, and now 60% of scanner time is devoted specifically to cardiac cases, Shah said.

"What is most striking is the volume of stress cases. They have increased from 7% to nearly one-third of the studies. Stress cases are the most time-consuming cases in the mix, but that is where the need lies," Shah said.

Productivity improved as the staff was expanded, leading to the center's successful response to demand. Initially, Shah, who previously practiced with Dr. Raymond Kim's group at Duke University, was the only cardiologist assigned full-time to the CMR operation. He worked with two imaging technologists and a nurse. Three CMR-trained cardiologists have since joined Shah, along with three technologists, four nurses, and a cardiac MR research fellow from Duke.

Average scanning times for stress, function and viability, and vascular imaging all fell as new staff gained experience. Over the first 18-month period, the average time for stress imaging shed 35 minutes, while functional and viability and vascular workups were typically finished 30 and 22 minutes faster, respectively, than their original times (Figure 2). Mean turnover times fell from 31 to 14 minutes (Figure 3).

Shah has attempted to weed out inefficiencies at every point from preparation of the order to presentation of results. The process begins with the referring physician order sheet, which lists all possible indications and applications of CMR. The form simplifies ordering and, by forcing physicians to repeatedly examine the list, it informs them about all of CMR's various applications.

The form also requires the physician to summarize the patient's medical history and covers CMR's contraindications. Because many referring physicians are still unfamiliar with MR, Shah makes sure its contraindications are covered early and often.

"By having a prompt on the sheet itself, we avoid scheduling many patients who can't be done because of contraindications," he said.

The consumer learns CMR basics from a brochure prepared by the imaging center and distributed by its referring physicians. It specifies key points, such as the need for the patient to plan around CMR's hour-long scanning times, contraindications, and possible claustrophobic reactions.

PREPPING FOR PATIENTS

The night before imaging, the patient's chart is pulled. Patients requiring preparation for stress testing are identified. The chart is also examined for evidence of possible contraindications. The nurse usually calls the patient the day before the procedure to screen for contraindications and provide instructions about caffeine intake restrictions and procedural basics.

Patients, told to plan on 2.5 hours for the appointment, are instructed to arrive an hour before scanning commences to undergo metal screening, ECGs, and the installation of intravenous access devices. Patients at risk for claustrophobia are asked to arrange for transportation assistance because of possible sedation.

Assigning personnel to specialize in specific tasks maximizes workflow efficiency. Patients awaiting imaging are ready outside the suite as the previous appointment is completed. One technologist scans patients, while another tech performs postprocessing quantification and image reconstruction. Postprocessing is often completed before the patient leaves the scanner, Shah said.

The radiologist contributes to the productive flow by striving to complete interpretations in synch with the appointment calendar. The radiologist works in the physician's office at a workstation dedicated to the task and generally finishes the report while the next patient is being imaged. An automated report generator, featuring dropdown menus and formatted text pages, enables the clinician to transmit a signed report to the referring physician within hours of scanning.

Such responsiveness has contributed to the service's growth, according to Shah.