Low coronary blood flow causes acute coronary syndromes (ACS), angina pectoris, myocardial infarction, impaired left ventricular (LV) function, heart failure, arrhythmia, and death. High coronary blood flow capacity associates with cardiovascular health; its variations, reflecting our emotional states, lifestyles, and food, even the postprandial lipid surge of the last meal, are all documented to alter coronary blood flow and risk factors, symptoms, and outcomes of coronary artery disease. Evolving from 200 million years ago, concepts regarding the mammalian heart—coronary blood flow, human gender evolution, fluid dynamic equations, coronary pressure flow measurements, quantitative perfusion imaging, diagnostic tests, coronary artery disease in women versus men, and how poor coronary flow is optimally treated—constitute a highly integrated continuum, a syncytium of knowledge immediately relevant to current cardiovascular medicine and patient well-being.
Resurgent interest in coronary blood flow related to myocardial “ischemia” derives, in part, from substantial disconnects in cardiovascular medicine. Immediate percutaneous coronary intervention (PCI) in ACS reduces myocardial infarction and cardiovascular mortality.1 However, all elective revascularization trials driven by “ischemia” on diagnostic testing fail to reduce myocardial infarction or cardiovascular deaths despite relief of angina2,3,4,5,6,7,8,9 (Fig. 34–1).
Outcomes in (A) patients with non-ST-segment elevation acute coronary syndromes in the FRISC-II, RITA-3, and ICTUS trials, (B) patients with stable coronary artery disease at 12-year follow-up of the COURAGE trial, and (C) and (D) in patients with coronary artery disease and left ventricular dysfunction in the STICH trial with (red line) and without (blue line) ischemia by single-photon emission tomographic perfusion imaging. CI, confidence interval; PCI, percutaneous coronary intervention. A reproduced with permission from Fox KA, Clayton TC, Damman P, et al: Long-term outcome of a routine versus selective invasive strategy in patients with non-STsegment elevation acute coronary syndrome a meta-analysis of individual patient data. J Am Coll Cardiol. 2010 Jun 1;55(22):2435-2445. B reproduced with permission from Sedlis SP, Hartigan PM, Teo KK: Effect of PCI on Long-Term Survival in Patients with Stable Ischemic Heart Disease. N Engl J Med. 2015 Nov 12;373(20):1937-1946. C and D reproduced with permission from Panza JA, Holly TA, Asch FM, et al: Inducible myocardial ischemia and outcomes in patients with coronary artery disease and left ventricular dysfunction. J Am Coll Cardiol. 2013 May 7;61(18):1860-1870.
This disconnect even reaches into the legality of fully informed consent wherein “cardiologists (95%) in this sample did not inform the patient that PCI would not lower the risk of death or MI [myocardial infarction], or that the symptom benefit is gone after 5 years.”10,11 This issue is particularly relevant in view of only half of procedures being classified as appropriate out of 145,000 elective PCIs of the National Cardiovascular Data ...