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Patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) who either present with heart failure (HF) or develop the condition during hospitalization have a nearly twofold higher risk of dying within 30 days, according to a meta-analysis published in the June 2013 issue of JACC: Heart Failure. The analysis also identified differences in medical therapy and intervention that hint at possible undertreatment in this high-risk subgroup. 

Investigators led by Renato D. Lopes, MD, PhD, of Duke University Medical Center (Durham, NC), looked at pooled data from 46,519 NSTE-ACS patients enrolled in 7 randomized clinical trials conducted between 1994 and 2008.

HF Fairly Common

Of the overall study population, 4,910 patients (10.6%) had HF at presentation (defined as Killip classes II/III), while 1,194 (2.9%) developed HF during hospitalization (defined as no HF at presentation but a complication of HF or pulmonary edema noted in the study case report form).

Treatment with aspirin and lipid-lowering drugs was similar between patients with or without HF. However, beta-blockers were less commonly prescribed for patients with HF at presentation than those without (69.3% vs. 76.1%), while ACE inhibitors were more commonly given to those with any HF (64.9% vs. 47.1%). In addition, compared with their HF-free counterparts, patients with the condition were less likely to undergo catheterization (62.3% vs. 70.3%) or PCI (23.4% vs. 33.1%).

Multivariable regression analysis identified multiple predictors of HF during hospitalization, including:

• Older age, per 5-year increase (OR 1.3; 95% CI 1.23-1.31)
• Higher presenting heart rate (> 50 bpm), per 10 beats/min increase (OR 1.2; 95% CI 1.12-1.20)
• Diabetes (OR 1.6; 95% CI 1.41-1.84)
• Prior MI (OR 1.5; 95% CI 1.27-1.66)
• MI at enrollment (OR 1.9; 95% CI 1.63-2.18)

Similar baseline factors were associated with HF at presentation.

At 30 days, patients who presented with HF exhibited a fourfold higher mortality rate (5.2% vs. 1.3%) and an increased incidence of MI (11.1% vs. 8.4%; both P < 0.001) compared with those who did not. Overall, patients with HF either at presentation or during hospitalization were at increased risk of death and death or MI compared with those without HF (table 1).

Table 1. Thirty-Day Risk: Adjusted OR (95% CI)

Of the one-third of patients whose ejection fraction was quantitatively assessed, the median value was lower in those with vs. without baseline HF (49% vs. 55%) as well as in those with vs. without in-hospital HF (45% vs. 55%).

HF Patients Shortchanged on Intervention

The authors say the finding that patients with HF were less likely to receive intervention is consistent with results of the earlier OASIS-2 and GRACE registry studies. Moreover, in the GRACE study, HF patients who underwent PCI had lower rates of mortality after discharge than those who did not receive revascularization, “suggesting that a broader application of revascularization in this high-risk group may be beneficial,” the researchers add.

Dr. Lopes and colleagues also note that some of the factors predicting increased risk of HF in the hospital, such as elevated heart rate and lower blood pressure, vary over the course of treatment. “Thus, close attention to patients with those baseline characteristics in this setting might prompt treatment, such as earlier inhibitors of the renin-angiotensin-aldosterone system, which might [in turn] help prevent the development of HF and improve patient outcomes as a result,” they write.

The investigators acknowledge that since the analyzed trials occurred over a 14-year period, treatment of NSTE-ACS patients may have changed considerably over that time. In addition, lack of specific data on the timing of HF makes it uncertain whether HF occurring during hospitalization was new-onset HF or a consequence of a previous condition. Also unknown is whether other in-hospital complications may have occurred before or after the development of in-hospital HF.

Because patients with HF were undertreated with evidence-based therapies and interventions, an opportunity exists “to reduce adverse outcomes through adherence to guidelines recommendations,” the authors conclude.

Study Details

Patients with HF were older and less often male or current smokers. Multiple comorbidities and cardiac risk factors were more common among patients with HF. In particular, prior HF was 4 times more frequent among those who either presented with HF or developed the condition during hospitalization. In addition, at presentation more patients with HF had an MI and ST-segment changes on ECG, their heart rate was higher, and their blood pressure was lower than those without HF.

Source:

Bahit MC, Lopes RD, Clare RM, et al. Heart failure complicating non-ST-segment elevation acute coronary syndrome: Timing, predictors, and clinical outcomes. J Am Coll Cardiol HF. 2013;1:223-229.

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