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Position Paper: Distinguish Type 1 and Type 2 MI in Readmission Reduction Program

Key findings

  • The Hospital Readmissions Reduction Program (HRRP) imposes financial penalties on hospitals whose 30-day admission rates for certain conditions exceed risk-standardized readmission rates
  • Both type 1 and type 2 myocardial infarction are included in the HRRP, even though type 2 is more medically complex and there are no evidence-based treatment options
  • In a call to action, cardiologists at Mass General discuss several specific concerns about the HRRP, including the likelihood that the program underestimates the risk of readmission of patients with type 2 MI
  • The authors conclude that the HRRP should differentiate between patients with type 1 and type 2 MI

In the United States, the Hospital Readmissions Reduction Program (HRRP) aims to reduce 30-day readmissions in the Medicare population. Acute-care hospitals pay financial penalties if their 30-day admission rates for certain conditions exceed risk-standardized readmission rates.

Acute myocardial infarction is one of the targets of the HRRP, and the program does not distinguish between type 1 and type 2 MI. Type 1 MI, also known as a “classical” MI has a defined pathophysiology and treatment strategies. In contrast, type 2 MI—held to represent ischemic injury from supply/demand imbalance—is much less well understood and lacks defined therapy options.

In a position paper in the Journal of the American College of Cardiology, James L. Januzzi, Jr., MD, and colleagues review the ways in which type 2 MI is more medically complex than type 1 and present multiple arguments for having the HRRP distinguish between the two conditions.

The authors explain that patients with type 2 MI are a heterogeneous cohort, but are typically older than those with type 1 MI and have a worse prognosis. With type 2 MI, there is a higher prevalence of hypertension, hyperlipidemia, anemia, chronic kidney disease or prior stroke, and patients are more likely to have had hemodynamic instability, tachycardia, hypoxemic respiratory failure, decompensated heart failure or recent surgery.

Accordingly, research has shown that type 2 MI is associated with significantly higher rates of major cardiovascular adverse events, heart failure, all-cause death and cardiovascular death compared with other MI types. The five-year mortality rate for type 2 MI is estimated to be 60% to 65%.

The readmission rate following type 2 MI is uncertain, but the authors find it reasonable to suspect that it leads to a substantial amount of penalty funds under the HRRP. They present several concerns, including:

  • Potential underestimation of the risk of readmission: Medicare established the risk-standardized readmission rates for acute MI using claims data from July 2008 through June 2011. Yet the diagnosis of type 2 MI wasn't introduced until 2007, and no diagnostic code was available until October 2017. Therefore, patients with type 2 MI were probably underrepresented in risk estimates
  • Potential for undercoding: Physicians who are reluctant to contribute to a penalty for readmission may decide against assigning a diagnosis of type 2 MI. Without accurate coding, it will be challenging to improve processes of care for this illness. What's worse, other physicians may not recognize the severity of the patient's condition if the diagnosis is not recorded correctly
  • Potential to worsen inequalities: Older patients who have comorbidities that put them at risk of type 2 MI may more frequently go to safety-net hospitals, which already bear financial penalties disproportionately. Worsening those inequalities may discourage access and care of certain low-income and minority populations
  • Lack of accepted treatment strategies: In stark contrast to patients with type 1 MI, those with type 2 have no evidence-based treatment options, and there are no guideline or consensus statements on how they should be managed. The authors say it seems unreasonable to hold hospitals accountable for the readmission of these patients when there are no established strategies for reducing 30-day readmission rates. Furthermore, many patients with type 2 MI are readmitted because of their comorbidities, not for cardiovascular reasons

The authors conclude that the HRRP should differentiate between patients with type 1 and type 2 MI, in recognition of the different patient characteristics, prognosis and degree of certainty about management.

Refer a patient to the Mass General Heart Center

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