Demand Ischemia Management

Pathophysiology and Diagnosis

Demand ischemia occurs due to an imbalance between myocardial oxygen supply and demand, resulting in subendocardial ischemia, and can be caused by reduced myocardial oxygen delivery, elevated ventricular filling pressures, increased oxygen demand, and can occur even without significant coronary artery stenosis, as stated by the American Heart Association 1
NT-proBNP levels can be markedly elevated in demand ischemia due to direct release from myocardium as a result of end-diastolic wall stress, myocardial ischemia, and correlation to the degree of myocardial damage, according to the European Society of Cardiology 1, 2
In patients with acute coronary syndromes, median NT-proBNP levels can reach 203.5 pg/mL in acute myocardial infarction, 77.9 pg/mL in unstable angina, and 27.7 pg/mL in patients without acute coronary syndrome, as reported by the American College of Cardiology 2
NT-proBNP levels can exceed 12,000 pg/mL in severe cases like cardiogenic shock with AMI, as stated by the European Heart Journal 3

Demand ischemia can be distinguished from other chronic pathologies by cardiac biomarker patterns, echocardiography findings, and NT-proBNP levels, according to the American Heart Association 1, 2, 4
Heart failure typically has NT-proBNP levels >400 pg/mL for BNP and age-stratified cutoffs for NT-proBNP, as stated by the European Society of Cardiology 5, 6
Acute pulmonary embolism has high-risk patients with BNP >500 pg/mL, as reported by the European Heart Journal 6

The American College of Cardiology recommends identifying and addressing precipitating factors that create oxygen supply-demand imbalance, such as tachyarrhythmias, hypertensive crisis, severe anemia, hypoxemia, and thyrotoxicosis 1, 4
The European Society of Cardiology suggests laboratory evaluation, including serial cardiac biomarkers, complete blood count, electrolytes, renal function, and thyroid function tests 4, 7
The American Heart Association recommends imaging and functional assessment, including echocardiography to evaluate ventricular function, wall motion abnormalities, and valvular function, and consideration of coronary angiography in selected patients 4, 7, 8
Treatment strategy should focus on correcting the underlying cause, controlling heart rate and blood pressure, treating anemia, hypoxemia, or infection, and managing volume status with diuretics if volume overloaded, as stated by the European Society of Cardiology 2, 5, 6
Pharmacologic therapy should include initiation or optimization of heart failure medications, such as diuretics, ACE inhibitors, or vasodilators, which can result in measurable decreases in NT-proBNP levels, according to the American College of Cardiology 2, 5, 6