Nearly 10% of patients who underwent percutaneous coronary interventions during a 10-year period were readmitted to the hospital within 30 days, according to a single-center study published online Nov. 28 in Archives of Internal Medicine.
And those who were readmitted had approximately twice the risk of dying within a year, compared with those who were not readmitted, said Dr. Farhan J. Khawaja of the division of cardiovascular diseases at the Mayo Clinic, Rochester, Minn., and associates.
Thirty-day readmission rates after PCI are to be publicly reported and will be tied to hospital reimbursement, so there is great interest in determining what those rates are and how to improve them. "Prior to this study, knowledge of readmission rates after PCI was limited to administrative data from Medicare patients," who account for less than half of all PCI procedures, Dr. Khawaja and colleagues said.
They analyzed data in the Mayo Clinic’s PCI registry concerning 15,498 hospitalizations for PCI performed between 1998 and 2008 electively or for acute coronary syndromes. Overall, 1,459 cases (9.4%) required readmission within 30 days (Arch. Intern. Med. 2011 Nov. 28 [doi:10.1001/archinternmed.2011.569]).
There were 106 deaths (0.68%) within 30 days, including 33 that were associated with readmission and 73 that were not.
Most readmissions were for cardiac-related reasons. A total of 4.2% of patients were readmitted for repeat PCI, and another 4.7% were readmitted for coronary artery bypass grafting.
Thirty-day readmission was associated with significantly higher mortality. Patients who were readmitted had a 12-month mortality of just under 8%, compared with just under 4% for those who were not readmitted.
After multivariate analysis, demographic factors that were found to be associated with readmission were female sex, Medicare coverage (as opposed to any other type of insurance), and less than a high school education. None of these are modifiable, the investigators noted.
Other factors that were found to be associated with readmission were the presence of heart failure at presentation; concomitant renal disease, chronic obstructive pulmonary disease, peptic ulcer, or metastatic cancer; and a length of stay of more than 3 days. These variables also are not modifiable.
In previous studies, a lack of early follow-up care had been associated with increased readmissions, in part because patients may not fully understand and comply with maintenance therapies. In this study, "gaps in transitions in care from the inpatient to the outpatient context may account for many of the observed readmissions, especially among Medicare, Medicaid, and uninsured patients, who may experience difficulty in accessing outpatient care," Dr. Khawaja and associates said.
"The educational component of follow-up cannot be underestimated because in one study, less than half of patients were able to list their diagnoses and the names, purposes, and adverse effects of their medications at the time of discharge," the investigators noted.
Given that the factors associated with readmission are not modifiable and that follow-up care is modifiable, "interventions to improve access and follow-up care should be studied to assess [their] impact on readmission rates," the researchers said.
This study was not designed to determine whether any of the observed associations were causal. There also were no data on follow-up visits, medication compliance, health literacy, patient frailty, or other barriers to health care access, they said.
This study was funded by the Mayo Clinic’s division of cardiovascular diseases. One of Dr. Khawaja’s associates reported ties to United Healthcare, Medtronic, and the National Heart, Lung, and Blood Institute.