Postprocedural hs-TnT levels may not aid mortality risk prediction after PCI
medwireNews: Postprocedural elevations in high-sensitivity troponin T (hs-TnT) levels are not associated with increased mortality risk independently of baseline levels among patients undergoing percutaneous coronary intervention (PCI), researchers report.
“In patients with CAD undergoing elective PCI, the baseline level of hs-TnT was strongly and independently associated with 3-year mortality, whereas post-procedural hs-TnT elevations did not provide additional prognostic information beyond the baseline hs-TnT level,” write study authors Gjin Ndrepepa (Deutsches Herzzentrum München, Technische Universität, Germany) and colleagues in the Journal of the American College of Cardiology.
The authors separated the study participants into two groups, 2163 patients with baseline elevation in hs-TnT (>0.014 µg/L), and 3463 with normal baseline levels of hs-TnT (≤0.014 µg/L). Patients were followed up for up to 3 years.
In the group with baseline hs-TnT elevation, there were 155 deaths (18.2%) among patients with further hs-TnT elevation following PCI, compared with 50 deaths (16.0%) among patients with no further rise in hs-TnT, a nonsignificant difference (hazard ratio [HR]=1.09).
However, those with baseline hs-TnT elevation who had a very high postprocedural rise of more than 70 times the 99th percentile upper reference limit cutoff had a greater risk of mortality than those with a smaller rise (45.1 vs 17.1%, HR=4.20). Approximately 2% of patients with baseline hs-TnT elevation had a postprocedural rise above this threshold.
Among patients with normal hs-TnT levels at baseline, elevated postprocedural hs-TnT was associated with a significantly increased risk of mortality compared with normal postprocedural levels (HR=2.38). In this group, there were 54 deaths (3.8%) among patients with raised postprocedural hs-TnT levels, compared with six deaths (1.6%) among those with levels in the normal range following PCI.
In adjusted analyses accounting for factors associated with mortality risk – including female gender, diabetes, body mass index, and hypercholesterolemia – baseline hs-TnT, but not peak postprocedural hs-TnT, was significantly associated with increased mortality risk, with corresponding HRs of 1.22 and 1.04.
The author of an accompanying commentary, Sorin Brener (New York Methodist Hospital, Brooklyn, USA), believes that the study findings add “significantly to our appreciation of the risk associated with PCI,” but cautions that understanding or being able to estimate risk “is not the same as mitigating it.”
“[A]ssuming that there is no prognostic information in post-PCI biomarkers may prevent us from implementing more aggressive medical therapies or interventions that may be required in patients at the highest risk,” he adds.
Brener concludes that future studies should “measure troponin levels both before and after PCI in well-designed state and national registries to learn more of what they have to teach us.”
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