Detection of a High Ratio of Soluble to Membrane-Bound LOX-1 in Aspirated Coronary Thrombi From Patients With ST-Segment-Elevation Myocardial Infarction.

Background The circulating level of soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) is a valuable biomarker of acute myocardial infarction (AMI). The most electronegative low-density lipoprotein, L5, signals through LOX-1 to trigger atherogenesis. We examined the characteristics of LOX-1 and the role of L5 in aspirated coronary thrombi of AMI patients. Methods and Results Intracoronary thrombi were aspirated by performing interventional thrombosuction in patients with ST-segment-elevation myocardial infarction (STEMI; n=32) or non-ST-segment-elevation myocardial infarction (n=12). LOX-1 level and the ratio of sLOX-1 to membrane-bound LOX-1 were higher in thrombi of STEMI patients than in those of non-ST-segment-elevation myocardial infarction patients. In all aspirated thrombi, LOX-1 colocalized with apoB100. When we explored the role of L5 in AMI, deconvolution microscopy showed that particles of L5 but not L1 (the least electronegative low-density lipoprotein) quickly formed aggregates prone to retention in thrombi. Treating human monocytic THP-1 cells with L5 or L1 showed that L5 induced cellular adhesion and promoted the differentiation of monocytes into macrophages in a dose-dependent manner. In a second cohort of AMI patients, the L5 percentage and plasma concentration of sLOX-1 were higher in STEMI patients (n=33) than in non-ST-segment-elevation myocardial infarction patients (n=25), and sLOX-1 level positively correlated with L5 level in AMI patients. Conclusions The level of LOX-1 and the ratio of sLOX-1 to membrane-bound LOX-1 in aspirated thrombi, as well as the circulating level of sLOX-1 were higher in STEMI patients than in non-ST-segment-elevation myocardial infarction patients. L5 may play a role in releasing a high level of sLOX-1 into the circulation of STEMI patients.

Age-dependent impact of new ESC-Guideline recommended door-to-balloon times on mid-term survival in acute ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention.

BACKGROUND: To investigate the age-dependent impact of the superfast door-to-balloon (D2B) times of ≤60min as recommended by the new ESC Guideline for patients with ST elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) on mid-term survival rates based on a single center registry dataset. PATIENTS AND METHODS: This study enrolled consecutive STEMI patients who underwent PPCI from Jan 1, 2009 through Sep 30, 2013. We compared demographics, clinical characteristics and the D2B-survival relationships between patients aged ≥65 and <65. RESULTS: The younger group comprised 242 patients (68%) aged <65 and the elder group consisted of 115 patients (32%) aged ≥65. In patients aged <65, the mortality rate decreased linearly with D2B time shortening (>90min vs. 61-90min vs. ≤60min=14.9% vs. 13.3% vs. 1.2%, P=0.001). Contrarily, shortening of D2B time was not associated with reduced mortality rate in patients aged ≥65 (>90min vs. 61-90min vs. ≤60min=23.5% vs. 19% vs. 18.9%, P=0.99). In younger patients but not the elderly, a D2B time of <60min has sufficient power to predict mortality with a sensitivity of 0.83, specificity of 0.74, and Youden index of 0.57. CONCLUSIONS: Our results show that the new ESC Guideline recommendation of D2B time ≤60min is associated with better survival rates in younger STEMI patients undergoing PPCI. Our findings stress the importance of guideline adherence to minimize reperfusion delay to improve survival in these patients.

Impact of Prolonged Door-to-Balloon Times on the Diastolic Function in Acute ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention.

BACKGROUND: Emerging evidence indicates that diastolic left ventricular (LV) function is a powerful outcome predictor after acute ST-elevation myocardial infarction (STEMI). We hypothesized that shorter door-to-balloon (D2B) times with early restoration of coronary perfusion may preserve diastolic LV function in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). METHODS: This study enrolled 340 consecutive STEMI patients who underwent PPCI with D2B times of < 90 min in 232 patients and D2B times ≥ 90 min in 108 patients, who all received subsequent echocardiographic examination within 48 hours of hospitalization. RESULTS: Although the LV ejection fraction was similar (50.92% vs. 51.66%, p = 0.573), the proportion of E/E' ratio > 15 was greater in patients with D2B times ≥ 90 min compared to those with D2B times < 90 min (44.4% vs. 30.6%, p = 0.013). Logistic regression analysis revealed that D2B time ≥ 90 min [odds ratio (OR): 1.82, 95% confidence interval (Cl): 1.04-3.17, p = 0.035] was an independent predictor for LV diastolic dysfunction. The effect was more prominent in patients ≥ 65 years of age (OR: 2.77, 95% CI: 1.09-7.00, p = 0.032), in whom the fraction of LV diastolic dysfunction increased proportionally with prolonged D2B times. CONCLUSIONS: Prolonged D2B time of greater than 90 min predicted LV diastolic dysfunction, particularly in aged subjects. D2B times shortening is important to preserve diastolic heart function after PPCI. KEY WORDS: Acute myocardial infarction; Diastolic dysfunction; Door-to-balloon time; Primary percutaneous coronary intervention.

Treatment of slow/no-reflow phenomenon with intracoronary nitroprusside injection in primary coronary intervention for acute myocardial infarction.

Slow/no-reflow phenomenon is a serious problem complicating primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) and is associated with a poor prognosis. From January 2002 to November 2002, 11 of the 70 consecutive patients with ST elevation AMI who were subjected to primary PCI using balloon angioplasty and/or stenting developed slow/no-reflow phenomenon (TIMI 1 flow in 2, TIMI 2 in 8, and TIMI 2.5 in 1). They were 10 men and 1 woman, aged 64 +/- 11 years (range, 46-81). The culprit vessels were six in the left anterior descending coronary artery, three in the right coronary artery, one in the left circumflex coronary artery, and one in saphenous vein graft. Multiple bolus doses (100 microg) of nitroprusside were injected into the index artery through the guiding catheter using a 3 ml syringe until the TIMI flow grade improved by at least one grade or the systolic pressure decline below 80 mm Hg (one patient). The total drug dose varied from 100 to 700 microg. Following the drug treatment, angiographic TIMI flow grade improved by at least one grade in 9 (82%) of the 11 patients (P = 0.007). The TIMI frame counts significantly decreased from 36 +/- 17 frame counts to 16 +/- 11 frame counts (P = 0.012). All patients were discharged without major adverse cardiovascular events. Intracoronary bolus injection of nitroprusside using a 3 ml syringe appears to be a feasible, safe, and effective technique for the management of slow/no-reflow phenomenon complicating primary PCI.