Nonthyroidal illness syndrome, hypothyroidism up risk of mortality, MACE in IHD patients

Nonthyroidal illness syndrome (NTIS) and hypothyroidism appear to increase the risk of all-cause mortality and major adverse cardiac events (MACE) in patients with ischaemic heart disease (IHD), suggests a recent study.

The databases of PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched from inception through 17 February 2020. Studies were considered eligible if they enrolled IHD patients, compared all-cause mortality and MACE of NTIS and hypothyroidism with those of euthyroidism, and provided adequate information for meta-analysis.

The investigators also extracted relevant information and numerical data for methodological assessment and meta-analysis.

Twenty-three studies met the eligibility criteria. The IHD population with NTIS had a higher risk of all-cause mortality (hazard ratio [HR], 2.61, 95 percent confidence interval [CI], 1.89–3.59) and MACE (HR, 2.22, 95 percent CI, 1.71–2.89) than that without. Similarly, the IHD population with hypothyroidism were at higher risk of all-cause mortality (HR, 1.47, 95 percent CI, 1.10–1.97) and MACE (HR, 1.53, 95 percent CI, 1.19–1.97) than that without.

Subgroup analysis revealed a significantly increased risk of all-cause mortality (HR, 3.30, 95 percent CI, 2.43–4.48) and MACE (HR, 2.19, 95 percent CI, 1.45–3.30) in the acute coronary syndrome (ACS) subpopulation with NTIS. Likewise, the ACS subpopulation with hypothyroidism showed a higher risk of all-cause mortality (HR, 1.67, 95 percent CI, 1.17–2.39).

“Future research is required to provide evidence of the causal relationship and to elucidate whether normalizing thyroid function parameters can improve prognosis,” the investigators said.