Death rates associated with in-hospital cardiogenic shock following acute MI decline in recent years

In recent years, death rates associated with in-hospital development of cardiogenic shock have declined among patients hospitalized with acute MI, according to a population-based observational study conducted at 11 medical centers in central Massachusetts.

The decrease coincides with hospitals using more evidence-based cardiac medications and coronary reperfusion/revascularization strategies than they did before following hospitalization for acute MI.

Meanwhile, the incidence rates of cardiogenic shock remained similar during the study, which lasted from 2001 to 2011.

Lead researcher Robert J. Goldberg, PhD, of the University of Massachusetts Medical School in Worcester, and colleagues published their results online in Circulation: Cardiovascular Quality and Outcomes on Feb. 16.

“Patients who developed cardiogenic shock in this study were at nearly 6-fold greater risk for dying during their index hospitalization than patients who did not develop shock,” they wrote. “Although the crude in-hospital death rates associated with cardiogenic shock decreased over time, these encouraging trends were further enhanced after controlling for several factors of prognostic importance among patients hospitalized with [acute MI] during the most recent years under study.”

The researchers noted that cardiogenic shock is the most common cause of mortality for patients hospitalized with acute MI. Although the use early and aggressive revascularization for cardiogenic shock and mechanical approaches may improve short-term survival, they mentioned that the approaches do not improve the prognosis of patients who develop cardiogenic shock.

In this study, they examined data from all 11 teaching and community hospitals in the Worcester metropolitan area and examined patients hospitalized with a discharge diagnosis of acute MI between 2001 and 2011. The patients did not have cardiogenic shock when they entered the hospital.

They defined cardiogenic shock as a systolic blood pressure of less 80 mm Hg without hypovolemia but associated with cyanosis, cold extremities, changes in mental status, persistent oliguria or congestive heart failure.

Of the 5,686 patients, the mean age was 69.9 years old, while 56.7 percent were men and 89.7 percent were white. In addition, 64.5 percent of patients said it was their first acute MI.

The patients admitted during the most recent years were more likely to be younger, white and obese, have previously undergone a PCI, have a greater prevalence of chronic comorbidities and be prescribed all evidence-based cardiac medications, including aspirin, ACE inhibitors, ARBs, beta-blockers and lipid lowering agents. They were less likely to have had “do not resuscitate” orders when admitted to the hospital and be transported to the hospital via ambulance.

During the study, 3.7 percent of patients developed cardiogenic shock, including 3.7 percent from 2001 to 2003, 4.5 percent from 2005 to 2007 and 2.7 percent from 2009 to 2011. The researchers said the differences were not significant in crude and multivariable adjusted analyses.

However, the death rates significantly declined from 47.1 percent from 2001 to 2003 to 42 percent from 2005 to 2007 and then to 28.6 percent from 2009 to 2011.

“Future studies remain needed to evaluate the efficacy of existing strategies for the prevention and management of cardiogenic shock during hospitalization for [acute MI] and the development of protocols to ensure the optimal utilization of effective treatment strategies,” the researchers wrote.