Clinical outcomes of patients with hypothyroidism undergoing percutaneous coronary intervention

Abstract

Aims: The aim of this study was to investigate the association between hypothyroidism and major adverse cardiovascular and cerebral events (MACCE) in patients undergoing percutaneous coronary intervention (PCI).

Methods and results: Two thousand four hundred and thirty patients who underwent PCI were included. Subjects were divided into two groups: hypothyroidism (n = 686) defined either as a history of hypothyroidism or thyroid-stimulating hormone (TSH) ≥5.0 mU/mL, and euthyroidism (n = 1744) defined as no history of hypothyroidism and/or 0.3 mU/mL ≤ TSH < 5.0 mU/mL. Patients with hypothyroidism were further categorized as untreated (n = 193), or those taking thyroid replacement therapy (TRT) with adequate replacement (0.3 mU/mL ≤ TSH < 5.0 mU/mL, n = 175) or inadequate replacement (TSH ≥ 5.0 mU/mL, n = 318). Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. Median follow-up was 3.0 years (interquartile range, 0.5-7.0). After adjustment for covariates, the risk of MACCE and its constituent parts was higher in patients with hypothyroidism compared with those with euthyroidism (MACCE: HR: 1.28, P = 0.0001; myocardial infarction (MI): HR: 1.25, P = 0.037; heart failure: HR: 1.46, P = 0.004; revascularization: HR: 1.26, P = 0.0008; stroke: HR: 1.62, P = 0.04). Compared with untreated patients or those with inadequate replacement, adequately treated hypothyroid patients had a lower risk of MACCE (HR: 0.69, P = 0.005; HR: 0.78, P = 0.045), cardiac death (HR: 0.43, P = 0.008), MI (HR: 0.50, P = 0.0004; HR: 0.60, P = 0.02), and heart failure (HR: 0.50, P = 0.02; HR: 0.52, P = 0.017).

Conclusion: Hypothyroidism is associated with a higher incidence of MACCE compared with euthyroidism in patients undergoing PCI. Maintaining adequate control on TRT is beneficial in preventing MACCE.

Keywords: Hypothyroidism; Major adverse cardiovascular and cerebral events; Percutaneous coronary intervention.

Figure 1

Patient selection process and study protocol.

Figure 2

Patient selection process by thyroid-stimulating hormone levels.

Figure 3

Frequency of adverse cardiovascular events at follow-up in patients with hypothyroidism and euthyroidism. Unadjusted Kaplan–Meier curves during 10-year follow-up for ( A ) major adverse cardiovascular and cerebral events, ( B ) cardiac death, ( C ) myocardial infarction, ( D ) heart failure, ( E ) target-vessel revascularization,and ( F ) stroke.

Figure 4

Frequency of adverse cardiovascular events at follow-up in patients with hypothyroidism, subclinical hypothyroidism, and euthyroidism according to serum thyroid-stimulating hormone levels. Unadjusted Kaplan–Meier curves during 10-year follow-up for ( A ) major adverse cardiovascular and cerebral events, ( B ) cardiac death, ( C ) myocardial infarction, ( D ) heart failure, ( E ) revascularization, and ( F ) stroke. EH, euthyroidism; SH, subclinical hypothyroidism; HP, hypothyroidism.

Figure 5

Hazard ratios for major adverse cardiovascular and cerebral events in patients with hypothyroidism, subclinical hypothyroidism, and euthyroidism.

Figure 6

Frequency of adverse cardiovascular events at follow-up between patients not taking thyroid replacement therapy and those taking thyroid replacement therapy with and without adequate replacement. Unadjusted Kaplan–Meier curves during 10-year follow-up for ( A ) major adverse cardiovascular and cerebral events, ( B ) cardiac death, ( C ) myocardial infarction, ( D ) heart failure, ( E ) target-vessel revascularization, and ( F ) stroke.

Figure 7

Hazard ratios for major adverse cardiovascular and cerebral events in patients taking thyroid replacement therapy with adequate replacement vs. inadequate replacement and no replacement therapy.

Figure 8

Kaplan–Meier-estimated cumulative target and downstream disease progression frequencies during 10-year follow-up. ( A ) Target-lesion disease progression and ( B ) downstream disease progression.