[Influence of leukocytes on coronary flow reserve, left ventricular systolic function, and in-hospital events, in patients with acute anterior myocardial infarction treated by primary angioplasty]

[Incidence, associated factors, and follow-up of hospital heart failure complicating acute anterior myocardial infarction successfully treated by primary angioplasty]

Heart failure (HF) complicating acute myocardial infarction (AMI) is of poor prognosis and is often associated with patient's characteristics and success of reperfusion strategies. However, few data is available regarding the high-risk subgroup of patients with anterior AMI treated successfully by primary angioplasty. The aim of the study was to assess the incidence, associated factors, and the future of HF occurring during hospitalisation, in the setting of anterior AMI treated successfully by primary angioplasty.

METHODS

Eighty-five consecutive patients with anterior AMI treated successfully by primary angioplasty (final angiographic TIMI flow grade=3, without residual stenosis) were included. Clinical, biochemical, angiographic, and echocardiographic data were prospectively collected and compared between patients with (Killip 2 and 3) and without HF during hospitalisation.

RESULTS

Fifteen patients had HF (18%) during hospitalisation and 70 did not. By comparison to patients without HF, patients with HF were more frequently diabetics, had troponin peak and CPK, leucocytes count, and fasting glucose higher, LVEF and wall motion score index in the left anterior descending territory (WMSi-lad) poorer, and a lower non-invasive coronary flow reserve (CFR) in the LAD 24hours after angioplasty (all, P<0.05). In multivariate analysis, fasting glucose, leucocytes count after angioplasty, CFR and WMSi-lad were independently associated with HF, even after adjusting with angiographic variables (all, P<0.05). At 6months, patients with HF had less recovery of LV function and higher frequency of adverse LV remodelling (58% versus 20%, P<0.01) by comparison to patients without HF.

CONCLUSION

In conclusion, HF is not uncommon even after successful primary angioplasty for anterior AMI (nearly one patient out of 5), is associated with hyperglycaemia and inflammation, a poor microvascular reperfusion, and left ventricular systolic function, and is more frequently complicated by adverse LV remodelling and lack of LV recovery.

[Non-invasive coronary flow reserve is an independent predictor of exercise capacity after acute anterior myocardial infarction]

BACKGROUND

After acute myocardial infarction (MI) coronary microvascular impairment and reduced exercise capacity are both determinant of prognosis.

OBJECTIVE

We tested whether non-invasive coronary flow reserve (CFR) performed after MI predicts post-MI exercise capacity (EC).

METHODS

Fifty consecutive patients (pts) (mean age 56.5±11years, 30% women) with a first reperfused ST-elevation anterior MI, and sustained TIMI 3 flow after mechanical reperfusion, underwent prospectively non-invasive CFR in the distal part of the left anterior descending artery (LAD), using intravenous adenosine infusion (0.14mg/kg per minute, within 2min), within 24h after successful primary coronary angioplasty (CFR 1), and 4±1.6months later after a period of convalescence and a cardiac rehabilitation program (CFR 2). CFR was defined as peak hyperaemic LAD flow velocity divided by baseline flow velocity. All pts also underwent semi-supine exercise stress echocardiography (ESE) the same day of CFR 2. ESE was performed at an initial workload of 25-30watts with a 20watts increase at 2-minute intervals. Beta-blockers were withheld 24h before ESE.

RESULTS

The mean CFR 2 increased significantly when compared to CFR 1 (2.9±0.65 versus 1.9±0.4, P<0.01). During ESE, percentage of maximal predict heart rate achieved was 82±12%, maximal workload 95±30watts, exercise duration 486±155s, the ratio of double product 3.1±0.8, and EC 5.8±1.1 metabolic equivalents. No ischemia was induced during ESE in all pts, and the degree of mitral regurgitation did not differ significantly between rest and exercise. CFR 2 was significantly correlated to all indices related to EC (all, P<0.01), whereas CFR 1 was correlated to LV systolic function at follow-up (P<0.05) but not to EC. In multivariate analysis including age, sex, and body mass index, CFR 2 remained an independent predictor of EC (P<0.01).

CONCLUSION

Contrarily to acute CFR, CFR at follow-up is an independent predictor of EC after reperfused anterior MI. This suggests that the improvement of the coronary microcirculation is closely linked to the physical aptitude after MI.