Predicting Functional Recovery After Coronary Chronic Total Occlusion Revascularization

Inclusion Criteria: * Patients with symptomatic and documented CTO confirmed by coronary angiography with TIMI 0 flow lasting ≥3 months Age ≥18 years Referred for percutaneous coronary intervention (PCI) Provision of written informed consent Exclusion Criteria: * Acute myocardial infarction within 7days (as Acute inflammation contaminates biomarkers, within 7 days of an acute MI, sST2, MHR, and PIIINP values will reflect the acute infarction, not the chronic CTO state. the measured inflammatory response to a fresh myocardial injury, not the stable inflammatory milieu of a patient with a chronic total occlusion) and also stress test is contraindicated post-recent MI . Severe valvular heart disease (aortic stenosis with peak velocity ≥4.0 m/s or mean gradient ≥40 mmHg; mitral regurgitation graded severe; or any valvular lesion requiring imminent intervention)- because it independently alters myocardial work indices and is a contraindication to stress echocardiography ) and any significant valvular lesion that may independently affect LV function and alter myocardial stress indices . Contraindications to stress echocardiography Life expectancy \<1 year due to non-cardiac comorbidity, as determined by the treating physician(ethical burden on vulnerable patients and for study integrity) Active infection (until clinical resolution or normalization of CRP or a return to the patient's baseline inflammatory state , -2 months post-infection is used in some inflammatory profiling studies- ) Inflammatory disease Rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, and similar conditions produce chronically elevated MHR and sST2 Atrial Fibrillation or Significant Arrhythmia (reliable myocardial work analysis cannot be performed without stable sinus rhythm. Hypertrophic Obstructive Cardiomyopathy or Significant LV Outflow Tract Obstruction (Dobutamine stress is contraindicated in HOCM because it can provoke dynamic obstruction and hemodynamic collapse . Additionally, HOCM independently alters myocardial work indices through pressure overload) Severe Renal Insufficiency (eGFR \<30 mL/min/1.73m²) sST2 and PIIINP are cleared partly by the kidney. In advanced renal failure, baseline levels are chronically elevated regardless of cardiac status, making ΔsST2 and ΔPIIINP uninterpretable Active Malignancy or Chemotherapy Within 6Months , Both sST2 and MHR are influenced by systemic inflammatory states, and chemotherapy directly alters monocyte counts, HDL levels, and fibrotic turnover Recent Stroke or Acute Neurological Event Within 3 Months sST2 is elevated after ischemic stroke and correlates with neurological deficit severity. MHR is also altered in acute stroke cohorts . Pregnancy (Standard precautionary exclusion)