Microvascular obstruction after primary percutaneous coronary intervention: pathogenesis, diagnosis and prognostic significance.

The primary goal in reopening an infarct-related artery is the restoration of myocardial tissue-level perfusion. In a variable proportion of patients with ST-elevation myocardial infarction, however, microcirculatory impairment may persist after epicardial coronary artery recanalization. This phenomenon is known as microvascular obstruction (MVO). Ischemic injury, reperfusion injury, and distal embolization along with the individual response to each of these mechanisms are variably involved in the pathogenesis of MVO in the single patient. Importantly, MVO is associated with a worse prognosis both at short- and long-term follow-up. MVO can be assessed in the cath-lab by simple angiographic indexes, such as Thrombolysis in Myocardial Infarction grade score and Myocardial Blush Grade, or by invasive measures of coronary flow pattern. Imaging techniques, such as myocardial contrast echocardiography or cardiac magnetic resonance, and ST-segment resolution on standard electrocardiogram are used in the days following reperfusion with the patient in the coronary care unit. In this article, we review the available data regarding pathogenesis, diagnosis and the prognostic significance of MVO after primary percurtaneous coronary intervention in ST-elevation myocardial infarction patients, with a brief highlighting on the crucial role of its prevention and its early detection.

Multiple coronary plaque ruptures in a patient with a recent ST-elevation acute myocardial infarction causing recurrent coronary instability.

Multiple plaque instability has been reported in about one-third of patients with ST elevation acute myocardial infarction (STEMI) and could be responsible for early recurrent instability after STEMI. Optical coherence tomography (OCT) is a high-resolution imaging technique that may help in detection and characterization of unstable coronary plaques. We present a case of multiple coronary instability in a patient with anterior STEMI where OCT has tailored an optimal diagnosis and treatment.

Very late stent thrombosis complicating a previously lost and partially crushed stent: demonstration by optical coherence tomography.

Stent thrombosis (ST) is the most dramatic complication of coronary stenting. Mechanisms of ST are multiple, including procedural and patient-related factors. A considerable burden of metal inside the coronary has been associated with ST as suggested by the higher rate of ST in case of multiple overlapping or complex two stents procedure in bifurcation lesions. However, occasional stent loss and failure to retrieve it may be a substrate of ST, especially if multiple layers of stent struts are incompletely crushed. Here, we describe a case of very late ST on a partially crushed stent previously lost inside the coronary circulation, using optical coherence tomography (OCT) for guidance during the procedure.

Late (3 years) follow-up of successful versus unsuccessful revascularization in chronic total coronary occlusions treated by drug eluting stent.

The success rate of recanalization of coronary chronic total occlusion (CTO) has improved in recent years, but the clinical benefit associated with successful CTO recanalization in the drug-eluting stent (DES) era is not well known. A cohort of 317 consecutive patients (mean age 65 ± 10, 84% men) with CTOs (defined as Thrombolysis In Myocardial Infarction [TIMI] flow grade 0 and duration >3 months) of native coronary vessels in which percutaneous coronary intervention was attempted was enrolled from June 2005 to March 2009. All successful procedures (196 patients) were performed by DES implantation. The incidence of major adverse cardiac events (MACEs; a composite of cardiac death, myocardial infarction, and repeat revascularization) was assessed during a mean follow-up period of 3 years. MACE predictors were assessed in clinical, angiographic, and procedural data, including procedural success. Patients with successful percutaneous coronary intervention experienced a significantly lower MACE rate compared to those with failed procedures (17 [9%] vs 32 [26%], p = 0.008). Patients with multivessel disease experienced MACEs more frequently than those with single-vessel disease (45 [22%] vs 4 [4%], p = 0.002). On multiple Cox regression analysis, the presence of multivessel disease and CTO opening failure were independent predictors of MACEs (hazard ratio 2.31, 95% confidence interval 1.17 to 4.96, p = 0.01, and hazard ratio 1.81, 95% confidence interval 1.33 to 4.12, p = 0.02, respectively). The worst prognosis was confined to patients with multivessel disease and failed procedures (hazard ratio 2.73, 95% confidence interval 1.21 to 3.92, p = 0.03). In conclusion, successful recanalization of CTOs with DES translates into a reduction of the 3-year MACE rate compared to failed procedures, and the worst prognosis is observed in patients with failed procedures and multivessel disease, a notion that might be taken into account in the management of patients with coronary CTOs.

Predictors of thromboxane levels in patients with non-ST-elevation acute coronary syndromes on chronic aspirin therapy.

High levels of thromboxane A2 (TxA2), a key mediator of platelet activation and aggregation, are associated with an increased risk of cardiovascular events. We aimed at assessing the predictors of higher plasma levels of TxB2, the stable metabolite of TxA2, in consecutive patients presenting with non-ST-elevation acute coronary syndrome (NSTE-ACS) on previous aspirin (ASA) treatment undergoing coronary angiography. Ninety-eight consecutive patients (age 61 ± 11, 75% males) with NSTE-ACS, on previous chronic ASA treatment, were prospectively enrolled in this study. Coronary disease extent was assessed by angiography according to the Bogaty score. In all patients, admission plasma levels of TxB2 (pg/ml) were measured by enzyme-linked immunosorbent assay, and patients showing TxB2 levels in the fourth quartile were compared to patients showing TxB2 levels in the lower quartiles. Multivariable logistic regression analysis showed that platelet count (odds ratio [OR] 1.18, 95% confidence interval [CI] 1.02-1.63, p=0.04), multivessel coronary disease (OR 1.37, 95% CI 1.13-3.67, p=0.03), and coronary atherosclerosis extent index (OR 1.91, 95% CI 1.45-6.79, p=0.001) were independent predictors of TxB2 level upper quartile. Of note, C-reactive protein serum levels were similar in patients with TxB2 levels in the upper quartile as compared to those in the lower quartiles (p=0.49). In conclusion, NSTE-ACS patients with severe coronary atherosclerosis may have incomplete suppression of TxA2 production despite chronic ASA therapy. This finding suggests that additional efforts should be made to lower TxA2 levels in patients with widespread coronary artery disease.

Impact of gender on clinical outcomes after mTOR-inhibitor drug-eluting stent implantation in patients with first manifestation of ischaemic heart disease.

BACKGROUND: Women have a worse outcome than men after percutaneous coronary intervention (PCI). However, in the drug-eluting stent (DES) era, limited data are available about the impact of gender-related differences on clinical outcome. Furthermore, many series have also included patients previously treated by coronary-artery bypass grafts or PCI, which may bias the evaluation of DES-related clinical events at follow up. We aimed to assess the impact of gender on clinical outcomes in a consecutive series of patients at first manifestation of coronary artery disease (CAD) undergoing PCI with mTOR-inhibitor DES. METHODS AND RESULTS: A total of 138 consecutive patients (age 64 ± 13 years, female gender 29%) undergoing successful mTOR-inhibitor DES implantation [sirolimus-eluting stent (SES); zotarolimus-eluting stent (ZES); and everolimus-eluting stent (EES)] for the treatment of stable chronic angina or an acute coronary syndrome, as their first clinical manifestation of CAD, were prospectively enrolled between February 2008 and May 2009. Major adverse cardiac events (MACE), defined as a combination of cardiac death, myocardial infarction (MI), and clinically driven target lesion revascularization (TVR) at 12-month follow up, constituted the endpoint of the study. Fifty-one (37%) patients received SES; 46 (33%) patients received ZES; and 41 (30%) patients received EES. At follow up, 21 (15%) patients experienced a MACE. Three (2%) patients had cardiac death, five (4%) had MI, while 13 (9%) patients underwent clinically driven TVR. MACE occurred more frequently in females than males [10 (25%) vs. 11 (11%), p = 0.05]. At Cox regression analysis, the only independent predictors of MACE were female gender and implantation of more than one stent [hazard ratio (HR) 3.70, 95% confidence interval (CI) 1.46-9.36, p = 0.006; HR 1.26, 95% CI 0.99-2.74, p = 0.01, respectively]. CONCLUSIONS: In conclusion, our finding suggests that women may have a worse outcome as compared with men after mTOR-inhibitor DES implantation.

Angiographic patterns of myocardial reperfusion after primary angioplasty and ventricular remodeling.

BACKGROUND: No reflow after primary percutaneous coronary intervention is a dynamic process and its reversibility may affect left ventricular (LV) remodeling. We aimed at assessing in-hospital evolution of angiographic no reflow, predictors of its reversibility, and its impact on LV function at follow-up (FU). METHODS: Fifty-three consecutive patients (age, 60±10 years; male sex, 79%) presenting with ST-elevation myocardial infarction and undergoing primary percutaneous coronary intervention within 12 h of symptom onset were enrolled. No reflow was defined as a final thrombolysis in myocardial infarction (TIMI) flow of 2 or final TIMI flow of 3 with myocardial blush grade (MBG) of less than 2. The evolution of angiographic no reflow was assessed by repeat in-hospital coronary angiography. Patients with no reflow found to have an improvement of TIMI and/or MBG leading to a final TIMI 3 and MBG of greater than or equal to 2 were classified as reversible no reflow; the remaining patients were classified as sustained no reflow. Variables predicting the patterns of no reflow, recorded on admission, were assessed among clinical, angiographic and laboratory data. FU echocardiographic data (at 6 months) were compared with those obtained in-hospital according to no reflow evolution. RESULTS: Thirty-six patients (68%) exhibited myocardial reperfusion; 17 patients (32%) showed no reflow. Among these, six patients (age, 58±10 years; male sex, 83%) showed sustained no reflow, whereas 11 patients (age, 55±8 years; male sex, 82%) showed reversible no reflow. Patients with sustained no reflow had longer time to percutaneous coronary intervention (261±80 min) compared with those with myocardial reperfusion (216±94 min) or reversible no reflow (237±76 min; P=0.008 and 0.05, respectively). Moreover, patients with sustained no reflow had a higher peak troponin-T levels (14.5 ng/ml; range, 7.5-20.2 ng/ml) compared with those presenting with myocardial reperfusion (3.9 ng/ml; range, 3.3-9.1 ng/ml) and reversible no reflow (7.7 ng/ml; range, 3.6-29.9 ng/ml; P=0.03 and 0.07, respectively). At multivariate ordinal logistic regression, time pre-PCI retained its statistical significant association with angiographic no reflow evolution (odds ratio=2.54; 95% confidence interval: 1.45-6.53; P=0.04), with troponin T levels showing a borderline statistical significance (odds ratio=3.12; 95% confidence interval: 1.07-6.23; P=0.09). Finally, in patients with sustained no reflow only both end-diastolic and end-systolic volumes significantly increased at FU (P<0.001 and 0.001, respectively). CONCLUSION: Sustained no reflow is associated with a longer ischemic time and predicts worse LV remodeling. No reflow, however, shows an in-hospital reversibility calling for therapeutic interventions when its prevention fails.