Early CVD Readmissions and Mortality Patterns Differ in Canada and the US

Rates of hospital readmissions and mortality within 30 days after acute MI in Ontario, Canada, are largely similar to what have been reported in the United States, but not so for heart failure patients, according to new registry data.

The United States has tracked hospital readmissions since 2012 through the Hospital Readmissions Reduction Program (HRRP), a controversial program that incentivizes a reduction in this metric. However, Canada has no such program.

“There's a lot of things that we still don't understand about the US readmission program. Some have argued that there's been unintended consequences that when you push people not to readmit the mortality has gone up,” lead study author Dennis Ko, MD, MSc (Sunnybrook Health Sciences Centre, Toronto, Canada), told TCTMD. “I don't think we answer a lot of questions with specific regards to hospital admissions programs, but I think [our study] does kind of create more discussion, more questions about that there are definitely differences when you look at these things over time.”

For the study, published in the February 25, 2020, issue of the Journal of the American College of Cardiology, Ko and colleagues looked at 152,808 acute MI and 223,283 heart failure patients ages 65 and older who were hospitalized between 2006 and 2017 across the province of Ontario. 

Over the study period, age- and sex-standardized hospitalization rates dropped by 32% for acute MI and 9.1% for heart failure.

For acute MI specifically, the co-primary outcome of risk-adjusted 30-day readmission declined from 17.4% in 2006 to 14.7% in 2017. Postdischarge mortality at 30 days—the other co-primary outcome— decreased from 5.1% to 4.4%.

Interestingly, among acute MI patients, postdischarge prescription increased for beta-blockers (from 75.6% in 2006 to 77.3% in 2017), statins (from 78.8% to 87.0%), and antiplatelet therapy from 54.0% to 82.2%). Prescriptions for ACE inhibitors/angiotensin receptor blockers (ARBs) fell from 75.7% to 71.9%.

In heart failure, the overall risk-adjusted 30-day readmission rate remained largely unchanged between 2006 and 2014 at 21.9%, with a drop to 20.8% in 2017. Risk-adjusted 30-day postdischarge mortality declined from 7.1% in 2006 to 6.4% in 2015, followed by a slight increase to 6.6% in 2017.

For this cohort, beta-blocker use increased from 58.4% in 2006 to 69.5% in 2017, while prescriptions for ACE inhibitors/ARBs decreased from 68.9% to 51.9%.

“The findings contrast with results reported from the United States,” Ko and colleagues write. “Concordant with the United States, there were significant reductions in admission rates, risk-adjusted readmissions, and mortality in patients with AMI. However, whereas the United States observed a large reduction in admission and readmission and a slight increase in postdischarge mortality among patients with HF, Ontario only experienced smaller declines in admission and readmission over time, but a qualitatively different result for mortality. The reasons underlying the diverging country-specific patterns for patients with HF are not clear, but should be concerning for the United States, who have had a trend of increasing postdischarge HF mortality since 2006 which preceded the readmission program.”

Additionally, the authors say that their observation of a decline in heart failure incidence but an increase in burden can be “attributed to an improvement of treatment of cardiovascular [conditions] and aging of the general population.” However, this “sharply contrasts” with US data, Ko and colleagues write. “The much larger reduction in heart failure admission in the United States could suggest a temporal change in the threshold of admitting patients with heart failure due to the discretionary nature of some admission decisions. Additionally, strategies to avoid heart failure admissions, such as the use of observational units, policy changes over the study period likely had a large impact on which patients with heart failure are being admitted in the United States.”

Future Outlook

As for where to go from here, at least in the United States, Ko said there are two options. “One is to say: let's fix the readmission program or try to change it. Number two is [to say] it’s working at least to some extent to help reduce readmission. But I think a lot of work needs to happen to make sure there aren’t really unintended consequences. A lot of groups are actively working on it, but I think more information is definitely needed.”

In an accompanying editorial, Jason Wasfy, MD, MPhil (Massachusetts General Hospital, Boston), writes that the study “will not resolve the debate on HRRP and mortality. But it should move the needle to focus more on health policy and care delivery in the United States. We must scrutinize all aspects of care processes for HF. We do not fully understand what is causing this worrisome increase in mortality or the worrisome trends in other areas of cardiovascular medicine.”

Commenting on the study for TCTMD, Ambarish Pandey, MD (University of Texas Southwestern Medical Center, Dallas), agreed. “It highlights that health policies do seem to affect readmission rates for different conditions in the US and also it tells us that the epidemiology of heart failure hospitalization may vary across different countries and health systems. So, we cannot basically use one strategy to understand readmissions and mortality across different countries. I think more work needs to be done to understand the evolution of heart failure readmissions and mortality over time in Canada as well as [in the United States].”

Even with remaining uncertainty, Wasfy says policies are needed to randomize metropolitan statistical areas in order to “facilitate more conclusive policy evaluation.” Also, “with respect to heart failure specifically, even as we work to understand the mortality trend, we must address known, shocking gaps in heart failure care delivery.” He proposed testing traditional care alternatives like telemedicine that might perform better than conventional office visits as well as payment models that “explicitly target improving goal-directed medical therapy for systolic heart failure.”

He concluded: “I there’s one thing we should all agree on about HRRP, it’s that large financial incentives can focus attention.”