Aborted myocardial infarction in intracoronary compared with standard intravenous abciximab administration in patients undergoing primary percutaneous coronary intervention for ST-elevation myocardial infarction.

BACKGROUND: Abciximab reduces major adverse cardiac events (MACEs) in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Intracoronary (IC) abciximab bolus application might be more effective than a standard intravenous (IV) bolus. So far the occurrence of aborted MI, a new therapeutic target of effective treatment in STEMI, has not been evaluated in IC versus IV abciximab administration in STEMI patients undergoing primary PCI. METHODS: To investigate the extent of aborted MI, 154 patients undergoing primary PCI were randomized to either IC (n=77) or IV (n=77) bolus abciximab administration with subsequent 12-hour intravenous infusion. For assessment of infarct size and extent of microvascular obstruction, all patients underwent late enhancement magnetic resonance imaging (MRI). Aborted MI was defined by major (≥ 50%) ST-segment resolution and a lack of subsequent cardiac enzyme rise ≥ 2 the upper normal limit. We also assessed the occurrence of true aborted MI defined as the absence of myocardial necrosis in MRI. RESULTS: The incidence of aborted MI was significantly higher in the IC group (p=0.04); true aborted MI was only observed in the IC abciximab group (p=0.01). At multivariable logistic regression analysis, IC abciximab application was a significant independent predictor of true aborted MI (p=0.03). Aborted MI patients had an excellent prognosis at 6-month follow-up with no MACE as compared to 24 events in patients with non-aborted MI. CONCLUSIONS: IC bolus application of abciximab in STEMI patients undergoing primary PCI results in a higher incidence of aborted MI and subsequent improved clinical outcome.

Prevalence and functional impact of lipomatous metaplasia in scar tissue following myocardial infarction evaluated by MRI.

OBJECTIVE: To retrospectively assess the prevalence and functional relevance of lipomatous metaplasia (LM) of the left ventricle in patients with chronic ischaemic heart disease (CIHD) using cardiac magnetic resonance imaging (cMRI) with steady state free precession (SSFP) sequences. METHODS: We examined 315 patients (248 male, mean age 63 +/- 10 years) with a history of CIHD by cMRI. Standard SSFP sequences were applied and results were correlated with findings from cardiac catheterisation and computed tomography. In a subgroup of patients with LM (LM+) the functional results were correlated with patients without LM (LM-) as controls matched for age, body mass index, gender and infarct size. RESULTS: Of 315 patients, 36 showed LM. LM+ patients showed a higher tendency to develop aneurysms compared with LM- (31% vs. 17%; not significant), but no differences in ejection fraction or volumetric parameters. LM occurred significantly more often in older infarcts and patients with hyperlipoproteinaemia, while other cardiac risk factors or medication did not have a significant influence on the development of LM. CONCLUSIONS: LM is a common finding (11%) in patients with CIHD. LM does not have a significant influence on global cardiac function or ventricular size, but on local function and probably also on the development of left ventricular aneurysms.

Takotsubo cardiomyopathy or myocardial infarction? Answers from delayed enhancement magnetic resonance imaging.

Takotsubo cardiomyopathy (TTC) mimics symptoms of acute myocardial infarction (MI) with transient left ventricular dysfunction, acute chest pain, electrocardiographic changes and minimal myocardial enzyme release in the absence of significant coronary artery disease. We describe the cases of two postmenopausal women with suspected MI undergoing coronary angiography. Both patients had unobstructed coronary arteries but left ventriculography showed apical ballooning. Delayed enhancement magnetic resonance imaging (MRI) revealed in one patient transmural enhancement in the distribution of a coronary artery compatible with MI and in the other patient no delayed enhancement consistent with viable myocardium and the diagnosis of TTC. Therefore cardiac MRI should be performed in all patients with suspected TTC for further differential diagnosis.

Differential diagnosis of suspected apical ballooning syndrome using contrast-enhanced magnetic resonance imaging.

AIMS: The apical ballooning syndrome (ABS) is a new diagnostic entity which is increasingly recognized. Precise magnetic resonance imaging (MRI) data are not yet available and there is little evidence for the differential diagnosis of ABS assessed by MRI. METHODS AND RESULTS: Between January 2005 and January 2008, 6100 consecutive patients with diagnosis of acute coronary syndrome underwent left heart catheterization. In 59 patients (1.0%), coronary angiography revealed normal coronary arteries, but left ventriculography showed left ventricular dysfunction with apical ballooning. These 59 patients underwent cardiac MRI using a 1.5 T MRI scanner. In 13 patients (22.0%), MRI revealed diagnosis of myocardial infarction, in eight patients (13.6%) diagnosis of myocarditis. In all other 38 (64.4%) patients (36 female, age 73 +/- 10 years) with suspected ABS, no delayed enhancement or signs of inflammation were detected. Follow-up MRI after 3 months showed a completely normalized left ventricular ejection in all patients with suspected ABS. Similarly, the end-diastolic volume and end-systolic volume improved at follow-up. CONCLUSION: Cardiac MRI allows differentiating ABS from other rare causes with unobstructed coronary vessels such as myocarditis and coronary emboli with spontaneous lysis. Therefore, cardiac MRI can add valuable information in all patients with suspected ABS for further differential diagnosis.

Intracoronary compared with intravenous bolus abciximab application in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: the randomized Leipzig immediate percutaneous coronary intervention abciximab IV versus IC in ST-elevation myocardial infarction trial.

BACKGROUND: Abciximab reduces major adverse cardiac events in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI). Intracoronary abciximab bolus application results in high local drug concentrations and may be more effective than a standard intravenous bolus. METHODS AND RESULTS: Patients undergoing primary PCI were randomized to either intracoronary (n=77) or intravenous (n=77) bolus abciximab administration with subsequent 12-hour intravenous infusion. The primary end point was infarct size and extent of microvascular obstruction as assessed by delayed enhancement magnetic resonance. Secondary end points were ST-segment resolution at 90 minutes, Thrombolysis in Myocardial Infarction flow and perfusion grades after PCI, and the occurrence of major adverse cardiac events within 30 days. The median infarct size was 15.1% (interquartile range, 6.1% to 25.2%) in the intracoronary versus 23.4% (interquartile range, 13.6% to 33.2%) in the intravenous group (P=0.01). Similarly, the extent of microvascular obstruction was significantly smaller in intracoronary compared with intravenous abciximab patients (P=0.01). Myocardial perfusion measured as early ST-segment resolution was significantly improved in intracoronary patients with an absolute ST-segment resolution of 77.8% (interquartile range, 66.7% to 100.0%) versus 70.0% (interquartile range, 45.2% to 83.5%; P=0.006). The Thrombolysis in Myocardial Infarction flow after PCI was not different between treatment groups (P=0.51), but there was a trend toward an improved perfusion grade (P=0.09). There also was a trend toward a lower major adverse cardiac event rate after intracoronary versus intravenous abciximab application (5.2% versus 15.6%; P=0.06; relative risk, 0.33; 95% CI, 0.09 to 1.05). CONCLUSIONS: Intracoronary bolus administration of abciximab in primary PCI is superior to standard intravenous treatment with respect to infarct size, extent of microvascular obstruction, and perfusion.