Acute insulin resistance in ST-segment elevation myocardial infarction in non-diabetic patients is associated with incomplete myocardial reperfusion and impaired coronary microcirculatory function.
BACKGROUND
Insulin resistance (IR) assessed by the Homeostatic Model Assessment (HOMA) index in the acute phase of myocardial infarction in non-diabetic patients was recently established as an independent predictor of intrahospital mortality. In this study we postulated that acute IR is a dynamic phenomenon associated with the development of myocardial and microvascular injury and larger final infarct size in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI).


METHODS
In 104 consecutive patients with the first anterior STEMI without diabetes, the HOMA index was determined on the 2nd and 7th day after pPCI. Worst-lead residual ST-segment elevation (ST-E) on postprocedural ECG, coronary flow reserve (CFR) determined by transthoracic Doppler echocardiography on the 2nd day after pPCI and fixed perfusion defect on single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) determined six weeks after pPCI were analyzed according to HOMA indices.


RESULTS
IR was present in 55 % and 58 % of patients on day 2 and day 7, respectively. Incomplete post-procedural ST-E resolution was more frequent in patients with IR compared to patients without IR, both on day 2 (p = 0.001) and day 7 (p < 0.001). The HOMA index on day 7 correlated with SPECT-MPI perfusion defect (r = 0.331), whereas both HOMA indices correlated well with CFR (r = -0.331 to -0.386) (p < 0.01 for all). In multivariable backward logistic regression analysis adjusted for significant univariate predictors and potential confounding variables, IR on day 2 was an independent predictor of residual ST-E ≥ 2 mm (OR 11.70, 95% CI 2.46-55.51, p = 0.002) and CFR < 2 (OR = 5.98, 95% CI 1.88-19.03, p = 0.002), whereas IR on day 7 was an independent predictor of SPECT-MPI perfusion defect > 20% (OR 11.37, 95% CI 1.34-96.21, p = 0.026).


CONCLUSIONS
IR assessed by the HOMA index during the acute phase of the first anterior STEMI in patients without diabetes treated by pPCI is independently associated with poorer myocardial reperfusion, impaired coronary microcirculatory function and potentially with larger final infarct size.
Department of Cardiology, Clinical Centre of Serbia, Ul, Koste Todorovica 8, 11000 Belgrade, Serbia. danijelatrif@gmail.com.
Danijela
D
Trifunovic
Sanja
S
Stankovic
Dragana
D
Sobic-Saranovic
Jelena
J
Marinkovic
Marija
M
Petrovic
Dejan
D
Orlic
Branko
B
Beleslin
Marko
M
Banovic
Bosiljka
B
Vujisic-Tesic
Milan
M
Petrovic
Ivana
I
Nedeljkovic
Jelena
J
Stepanovic
Ana
A
Djordjevic-Dikic
Milorad
M
Tesic
Nina
N
Djukanovic
Olga
O
Petrovic
Olga
O
Vasovic
Emilija
E
Nestorovic
Jelena
J
Kostic
Arsen
A
Ristic
Miodrag
M
Ostojic
D000208:Acute Disease; D000368:Aged; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D062645:Percutaneous Coronary Intervention / Q000379:methods; D011446:Prospective Studies