https://doi.org/10.1007/s00392-025-02625-4
1Medizinische Hochschule Hannover Kardiologie und Angiologie Hannover, Deutschland; 2Medizinische Hochschule Hannover Klinik für Nuklearmedizin Hannover, Deutschland
Background: Myocardial final infarct size (FIS) and microvascular obstruction (MVO) are associated with heart failure hospitalizations and mortality in patients undergoing primary percutaneous coronary intervention (pPCI) for acute ST-segment elevation myocardial infarction (STEMI). Interventional therapies beyond pPCI addressing reperfusion injury aiming for less MVO and smaller FIS are needed. Hyperoxemic supersaturated oxygen therapy (SSO2) has shown to reduce MVO and FIS in clinical trials.
Hypothesis: Routine use of SSO2 in every day’s clinical practice will reduce FIS and MVO in an extent that is relevant enough to lower rehospitalization for herat failure and mortality.
Methods: We performed routine intracoronary SSO2 (TherOx Inc., Irvine, CA, USA) therapy in patients with acute anterior STEMI after successful pPCI. Results from 20 SSO2 patients were compared with those from 20 matched non-SSO2 STEMI patients. Multimodal imaging including single-photon emission computed-tomography (SPECT), fibroblast activation protein inhibitor positron-emission tomography (FAPI-PET), and cardiac magnetic resonance imaging (CMR) was performed to assess left ventricular (LV) function, FIS, area-at-risk, myocardial salvage, and MVO.
Results: Both groups did not significantly differ regarding sex, age, weight, body mass index, hypertension, dyslipidaemia, smoking and diabetes status, prehospital cardiac arrest, door-to-balloon time, TIMI flow before and after PCI, and renal function (p>0.1 each) and had comparable area-at-risk by CMR and FAPI-PET. SSO2 patients showed lower maximum creatine kinase levels (1984 U/l) vs. non-SSO2 patients (4408 U/l, p<0.001). Primary endpoint: FIS determined by CMR was reduced from 32.3±6.9% in controls to 20.4±13.1% in SSO2-treated patients (p=0.005) and FIS determined by 99mTc- tetrofosmin perfusion SPECT was reduced from 29.2±14.4% in controls to 16.4±17.2% in SSO2-treated patients (p=0.014).
Secondary endpoint: Individual myocardial salvage as the fraction of FIS within the area of risk was determined by CMR and increased from 19±16% in controls to 47±27% in SSO2-treated patients (p=0.003). MVO determined by CMR was reduced from a median of 3.02% (IQR 1.18-7.56%) in controls to 0.08% (IQR 0.00-1.62%) in SSO2-treated patients (p=0.003).
Conclusion: While areas at risk were similar between both groups, SSO2 therapy significantly reduced MVO and FIS in patients with acute anterior STEMI undergoing pPCI in clinical routine practice.