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Updated: Mar 21, 2026
Myocardial Infarction and Functional Outcome Assessment in Pigs
Published on: April 25, 2014
Invasive Confirmation of Microvascular Recovery Parallel to Left Ventricular Functional Restoration
Takumi Toya1, Takumi Kondo2, Otoya Sekine2
1Department of Cardiology, NHO Tokyo Medical Center, Tokyo, Japan; Nishikoyama Toya Medical Clinic-Diabetes and Cardiovascular Care, Tokyo, Japan.
Background:
Coronary microvascular dysfunction (CMD) is increasingly implicated in heart failure, but reversal with guideline-directed medical therapy (GDMT) is rarely documented using invasive physiology.
Case Summary:
A 53-year-old man presented with paroxysmal nocturnal dyspnea. Electrocardiography showed precordial ST-T changes; brain natriuretic peptide was 419 pg/mL; left ventricular ejection fraction 35% with anteroseptal hypokinesis. Coronary angiography revealed intermediate proximal left anterior descending artery disease with nonischemic fractional flow reserve (0.84). Invasive indices indicated CMD (mean transit time [Tmn] 2.41/0.70 s; coronary flow reserve [CFR] 3.4; index of microvascular resistance [IMR] 59). After GDMT, left ventricular ejection fraction normalized (63%), and brain natriuretic peptide fell to 4.0 pg/mL at 3 months. Repeat physiology showed restored microvascular function (Tmn 0.84/0.20 s; CFR 4.2; IMR 15); fractional flow reserve remained nonischemic (0.82).
Discussion:
Marked improvement in IMR/CFR supports CMD-rather than epicardial stenosis-as the principal driver of the initial ischemic phenotype. GDMT may enhance microvascular vasodilator tone and myocardial energetics, improving CMD.
Take-Home Message:
Contemporary GDMT may favorably modulate the coronary microcirculation; improvement in CMD may parallel clinical recovery.
