Hospital Readmission Post-PCI Linked to Increased Mortality

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Nearly 1 in 10 patients who undergo percutaneous coronary intervention (PCI) are readmitted to the hospital within 30 days, and those patients are at an increased risk of death within 1 year, according to a study published online November 28, 2011, ahead of print in Archives of Internal Medicine. An accompanying research letter reinforces the connection between readmission and mortality in patients with ST-segment elevation myocardial infarction (STEMI).

For the main study, Henry H. Ting, MD, MBA, of the Mayo Clinic (Rochester, MN), and colleagues investigated 30-day readmission rates and 1-year mortality for PCI patients. They assessed 15,498 PCI hospitalizations (for elective, urgent, or emergent procedures) in 12,813 patients at a single institution (Saint Marys Hospital, Rochester, MN) from January 1998 through June 2008.

Readmission Linked with Mortality

Overall, 9.4% of patients were readmitted within 30 days.  In addition, 106 (0.68%) patients died within 30 days, 33 of them during or after a readmission.

Multivariate analysis identified several demographic and clinical factors associated with an increased risk of 30-day readmission after PCI (table 1).

Table 1. Factors Associated with 30-Day Readmission

Of the patients readmitted, 69% were for cardiac reasons, 4.2% had repeat PCI within 30 days of discharge, and 8.9% had PCI or CABG within 30 days of discharge.

Further, in analysis adjusted for factors associated with 30-day readmission, readmitted patients were more likely to die within 1 year (HR 1.38; 95% CI 1.08-1.75; P = 0.009).

Similarly, Gianluca Campo, MD, of Azienda Ospedaliera Universitaria Sant’Anna (Ferrara, Italy), and colleagues analyzed 11,118 STEMI patients undergoing primary PCI from the REAL registry from January 2003 to June 2009.

At 3-year follow-up, 1,779 patients had died, with a cumulative mortality of 12.1% at 1 year and 17.5% at 3 years. Of 7,867 readmissions, the conditions most commonly present were coronary revascularization (28%) and acute or congestive heart failure (26%).

After adjustment, the clinical factors with a significant impact (all P < 0.05) on mortality were:

• MI (HR 3.1; 95% CI 2.6-3.7)
• Stroke (HR 3.1; 95% CI 2.4-4.0)
• Coronary revascularization (HR 1.4; 95% CI 1.2-1.7)
• Acute or congestive heart failure (HR 3.5; 95% CI 3.0-4.0)
• Serious bleeding events (HR 4.1; 95% CI 3.6-4.8)
• Anemia (HR 3.7; 95% CI 2.8-4.9)

Generalizability Needed

In an editorial accompanying the original study, Adrian F. Hernandez, MD, and Christopher B. Granger, MD, both of Duke University (Durham, NC), write that “in the end, reducing hospital readmission rates by preventing progression of disease and occurrence of events should be a goal of care.” However, they comment that the model used to identify patients at risk for readmission in the original study “has relatively poor ability to discriminate risk, was developed on the sample from a single center in Minnesota, has not been validated, and may not be generalizable to other settings.”

In a similar vein, Stephen G. Ellis, MD, of the Cleveland Clinic (Cleveland, OH), told TCTMD in a telephone interview that the data would be more meaningful if they derived from a model that could classify patients more precisely.

“You need to better understand why these patients are getting readmitted,” he said. “You almost need a grid of risk factors versus reasons for readmission because those of us on the treatment end have to come up with some intervention that takes the high-risk patients and then does something with them so they don’t get readmitted so often.”

Reasons for Readmission

Dr. Ting and colleagues acknowledge that most of the factors they identified as being associated with a higher risk for 30-day readmission after PCI are not readily modifiable. Even so, “interventions to improve access and follow-up care should be studied to assess impact on readmission rates,” they write. 

In their editorial, Drs. Hernandez and Granger emphasize the importance of fully comprehending the reasons patients are readmitted before tackling the issue of reducing readmissions.

“Understanding whether readmissions are the result of procedural complications to electively staged procedures due to patient preferences, or to appropriate deferral procedures due to other medical conditions is critical,” they write. “In some cases, an elective readmission may be the most appropriate care rather than taking additional risk. In other cases, early outpatient follow-up to assess for procedural complications, medication adherence, or early clinical deterioration may be beneficial.”

Follow-up Is Key

Ajay J. Kirtane, MD, SM, of Columbia University Medical Center (New York, NY), agreed that readmissions are not always necessarily harmful, but he added that a main focus after PCI should be transition of care and adequate follow-up.

“One of the issues here is that a lot of emphasis is being placed on shortening hospital [lengths of stay],” he said in a telephone interview with TCTMD. “There are other ways of looking at it. When a patient comes into the hospital, this is a good opportunity to tune up their medications and to establish what their follow-up should be. So in a sense, if you use the initial hospitalization in that way, perhaps outcomes could be even better.”

Similarly, the literature suggests that high-risk patients have better outcomes if they see an advanced practice nurse within the first week of hospital discharge, Dr. Ellis noted, adding that “for the really high-risk patients, there are some internal monitors that look somewhat promising.”

In conclusion, “we need to better understand what is going on with patients before we can really come up with reasonable interventions to try and reduce the readmission rate,” Dr. Ellis said. “And then you have to try a few. Just because it makes sense doesn’t necessarily mean it’s going to work.”

  

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Sources:
1. Khawaja FJ, Shah ND, Lennon RJ, et al. Factors associated with 30-day readmission rates after percutaneous coronary intervention. Arch Intern Med. 2011:Epub ahead of print.

2. Campo G, Saia F, Guastaroba P, et al. Prognostic impact of hospital readmissions after primary percutaneous coronary intervention. Arch Intern Med. 2011:Epub ahead of print.

3. Hernandez AF, Granger CB. Prediction is very hard, especially about the future. Can we prevent events that lead to readmission following percutaneous coronary intervention? Arch Intern Med. 2011:Epub ahead of print.

 

• Dr. Hernandez reports receiving research support or consulting fees from AstraZeneca, Johnson & Johnson, Medtronic, Novartis Pharmaceutical, Proventys, Scios, and Thoratec.

• Dr. Granger reports receiving research support or consulting fees from Astellas Pharma US, AstraZeneca, Boehringer Ingelheim, Bristol-Myers Squibb, GlaxoSmithKline, Hoffman-La Roche, Lilly, Medtronic CardioVascular, Merck, Novartis Pharmaceutical, Otsuka Pharmaceutical, Sanofi-Aventis, and The Medicines Company.

 

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