The presence of hyperlipidemia (HLP) following hospitalization for acute myocardial infarction (AMI) or acute decompensated heart failure (ADHF) may be associated with reduced mortality, according to study results published in BMJ Open.
In this systematic review and meta-analysis, researchers evaluated adult patients who were hospitalized at the Mayo Clinic between 1996 and 2015 who with primary discharge diagnoses of AMI or ADHF. All patients were followed from index hospitalization until death or August 17, 2016, whichever occurred first. Researchers assembled 1:1 propensity score-matched pairs of patients with AMI or ADHF to balance differences in baseline variables between patients with vs without HLP. The study’s main outcome was all-cause mortality.
For the selection of final study cohorts, the AMI group had 13,680 patients in the initial cohort, 8696 patients in the propensity score-matched cohort, and 4348 patient-pairs. The ADHF group had 9717 patients in the initial cohort, 5758 patients in the propensity score-matched cohort, and 2879 patient-pairs.
In matched patients with AMI, mortality was found to be lower in those with vs without HLP (overall mortality, 50.2% vs 62.5%, respectively; 5.9 vs 8.6 deaths per 100 person-years of follow-up, respectively; P <.0001). Mortality was also lower in the matched patients with ADHF with vs without HLP (overall mortality, 58.6% vs 67.7%, respectively; 12.4 vs 16.3 deaths per 100 person-years of follow-up, respectively; P <.0001).
The magnitude of hazard ratios (HRs) for mortality associated with comorbidities including cancer, diabetes, and stroke was modestly reduced in patients with comorbid HLP in all cohorts. However, the protective effect of HLP on mortality was enhanced when it was combined with hypertension in patients with AMI (HR, 0.77; 95% CI, 0.72-0.83) and ADHF (HR, 0.86; 95% CI, 0.78-0.94). Meta-analyses on 9 observational studies indicated that HLP was associated with reduced mortality at ≥2 years after incident AMI (risk ratio [RR], 0.72; 95% CI, 0.69-0.76) or ADHF (RR, 0.67; 95% CI, 0.55-0.81).
Study limitations include the possibility of unmeasured confounders, and a reliance on classification codes to identify study cohorts.
“Our data support a protective role for HLP against all-cause mortality following incident AMI and ADHF,” concluded the study authors. “Further studies are needed to understand the complex relationship between HLP and mortality, especially in the presence of other competing comorbidities and to define appropriate HLP targets to maximize the benefits.”
Yousufuddin M, Takahashi PY, Major B, et al. Association between hyperlipidemia and mortality after incident acute myocardial infarction or acute decompensated heart failure: a propensity score matched cohort study and a meta-analysis. BMJ Open. 2019;9(12):e028638.