Hospitals may be doing a better job at treating incident MIs, but the increasing frequency of multiple morbidities among survivors may cloud this improved performance, according to a study on 30-day rehospitalizations that was published July 3 in the Annals of Internal Medicine. The findings put a spotlight on the use of rehospitalization as a quality metric.

The researchers found that about one in five patients who experience their first MI were readmitted to the hospital within 30 days, but less than half of rehospitalizations were related to the index MI or its treatment. The study, which tracked outcomes over more than two decades, showed that survival improved over time but that the frequency of multiple morbidities also increased.

“Patients who present with a heart attack nowadays don’t look like patients who presented 20 or even 10 years ago,” said senior author Veronique L. Roger, MD, MPH, of the health sciences research department at Mayo Clinic in Rochester, Minn., in an interview with Cardiovascular Business. Today’s incident MI patient may also have diabetes, hypertension, obesity or other morbidities, for instance. “They have this context of multimorbidity that requires that we envision care of the heart attack with a holistic approach.”

Roger and colleagues designed a retrospective cohort study using a population-based registry in one county in Minnesota to better understand patient- and treatment-specific factors behind rehospitalization of incident MI patients. They observed that rehospitalization is considered an indicator of the quality of care. While it is costly and frequent within 30 days, little is known about its trends over time.

They used the Rochester Epidemiology Project, which captures data on all incident MIs from initial diagnosis until death within a county served by three hospitals, two of which are in the Mayo Clinic system. They obtained data on patients admitted for a possible MI between 1987 and 2010. Data included all-cause hospitalizations within 30 days of hospital discharge for the incident MI. A total of 3,010 patients were diagnosed with an incident MI and survived the index hospitalization.

Among their findings:

• In-hospital survival improved over time, from 89 percent for a 1987 through 1992 period to 95.8 percent for 2005 through 2010;
• The frequency of hypertension, hyperlipidemia, diabetes, obesity, chronic obstructive pulmonary disease and anemia increased over time;   
• 10.3 percent of patients who underwent PCI had a complication, with vascular or bleeding complication being the most prevalent;
• 8.6 percent of patients were rehospitalized within 30 days of discharge;
• Among the rehospitalizations, 42.6 percent were related to the incident MI or treatment, while 30.2 percent were unrelated and 27.2 percent were unclear.

“What we found in the study is that not all readmissions are related to the initial diagnoses,” Roger said. What’s more, the proportion of MI-related rehospitalizations decreased over time, from 47.5 percent in 1987-1992 to 36.7 percent for 2005-2007.

“Survival after a heart attack has improved, not only in our dataset but across all studies that looked at survival after MI,” she continued. “We are more effective at treating patients early, after the onset of symptoms, and we are doing a better job of starting them on evidence-based medications, specifically for the heart attack.”

For cardiovascular physicians, these results appear to be a victory but because the patients' frequency of many morbidities has increased over time, the needle on readmissions may not have budged much. “It doesn’t mean it is a failure by any stretch of the imagination,” Roger said. “What it means is that we are still experiencing a burden on the healthcare system coming from these patients.”  

The 30-day readmission metric has been a hot button topic, most recently with the National Quality Forum reaffirming its decision to endorse all-cause unplanned 30-day hospital rehospitalization as a quality indicator. Readmissions remain the crux of the ongoing controversy, Roger said, and additional research may be warranted to determine whether readmissions as a measure is appropriate.

But Roger added that the study’s overarching message revolves around patient care. Given today’s complex patient population, physicians and hospitals will need to recalibrate and focus on the patient as a whole. “Our patients are getting older and sicker. We can’t lose sight that we are treating the patients, not the disease,” she emphasized.

Look for more on MI and heart failure quality measures in the September issue of Cardiovascular Business. To sign up for a free subscription, click here.