Comparison between Microvascular Integrity Indexes Assessed by Pressure/Doppler Wire and %FDG Uptake in AMI following Primary PCI

BACKGROUND AND OBJECTIVES : Microvascular integrity has been associated with the clinical outcomes in acute myocardial infarction (AMI). The present study was conducted to determine the value of many microvascular indexes assessed by an intracoronary (IC) pressure/Doppler wire in AMI following primary PCI for detecting viable myocardium by comparing with the 18F-fluorodeoxyglucose uptake rate (%FDG uptake) on positron-emission tomography (PET). SUBJECTS AND METHODS : We studied 35 patients who had their first AMI (age: 56+/-12, male: 30). After primary PCI, the TMPG (TIMI myocardial perfusion grade) was assessed. We measured the coronary flow reserve (CFR), the diastolic deceleration time (DDT), the coronary wedge pressure (Pcw), the Pcw/ Pa (mean aortic pressure) and the hyperemic microvascular resistance index (hMVRI) by an IC Doppler/ pressure wire. 18FDG PET scan was obtained at 7 days after the primary PCI; viable myocardium was defined that the %FDG uptake was more than 50% in infarct-related myocardium. RESULTS : There were significant correlations between TMPG, CFR, Pcw, Pcw/Pa, DDT, hMVRI and %FDG uptake (r=0.651, p<0.001; r=0.386, p=0.020; r=-0.388, p=0.021; r=-0.473, p=0.004; r=0.589, p<0.001; r=-0.442, p=0.008, respectively). The best cutoff values and area under curves (AUC) of the CFR, Pcw, Pcw/Pa, DDT and hMVRI for 50% FDG uptake were 1.8 (0.737), 27 mmHg (0.600), 0.33 (0.660), 600 msec (0.802) and 2.55 mmHg.cm-1.sec (0.768), respectively. The DDT had a significantly higher AUC than that of Pcw (p=0.029) and it was an independent index to predict the myocardial viability (p=0.011). CONCLUSION : DDT was the most reliable hemodynamic microvascular index that was assessed within 24 hours following primary PCI for predicting the viable myocardium in AMI patients.

Plaque Characteristics Related to Reducing the Coronary Flow Reserve after Stenting: an Intravascular Ultrasound Study

BACKGROUND AND OBJECTIVES: A reduction of the coronary flow reserve (CFR) following successful percutaneous coronary intervention (PCI) is related to microvascular impairment. Embolization of atherosclerotic debris during PCI is a possible explanation for the finding of abnormal coronary Doppler flow following PCI. SUBJECTS AND METHODS: The CFR and intravascular ultrasound (IVUS), both before and after PCI, were recorded in 69 lesions of 69 patients with coronary artery disease. An abnormal CFR was defined as one with no change or a decrease after successful PCI. RESULTS: The patients were divided into abnormal (n=17) and normal CFR (n=52) groups. After stenting, the hyperemic flow velocity was significantly lower in the abnormal CFR group (39.3+/-12.6 vs. 48.9+/-15.4 cm/s, p=0.022). 94 and 29% of the abnormal group had soft plaques and lipid cores, respectively, compared with 62 and 2% in the normal CFR group (soft plaque: p=0.029, lipid core: p=0.002). The abnormal CFR group had smaller post-procedural vessels (15.1+/-4.2 vs. 18.2+/-4.9 mm2, p=0.039) and plaque areas (6.8+/-2.7 vs. 9.9+/-3.8 mm2, p=0.006). Furthermore, the abnormal CFR group showed less vessel expansion (1.7+/-5.5 vs. 5.0+/-3.9 mm2, p=0.018) and greater plaque loss (4.1+/-5.3 vs. 0.7+/-3.4 mm2, p=0.009). The abnormal CFR group had an increased CK-MB following PCI (4 patients, 23.5% vs. 2 patients, 3.8%, p=0.029). In a multivariable analysis, the only predictor of an abnormal CFR was the presence of a lipid core within the plaque. CONCLUSION: Soft plaques, the presence of a lipid core and a large reduction in plaques increase the risk of microembolization during the PCI procedure.

Effects of Microvascular Integrity on the Evaluation of Fractional Flow Reserve and Epicardial Stenosis Resistance Index

BACKGROUND AND OBJECTIVES: The fractional flow reserve (FFR) and the hyperemic epicardial stenosis resistance index (hESRI) are known to be useful indexes for evaluating the hemodynamic severity of an epicardial coronary stenosis. However, the influence of the microvascular integrity of the distal segment of the lesion on the FFR and hESRI has not been clearly defined. SUBJECTS AND METHODS: A total of fifty-nine intermediate lesions of 51 patients (mean age: 58+/-11, 13 infarct-related arteries (IRA)) were studied. The area of stenosis (r-AS%) on the IVUS, the FFR, the coronary flow reserve (CFR) and the hESRI were measured before and after PCI. The hyperemic microvascular resistance index (hMVRI) of the distal site of the lesion was measured after PCI. The studied lesions were divided into two groups (Group 1, post-stent hMVRI2.09 mmHg.cm(-1).sec, n=21; 2.09 is the best cutoff value (BCV) for a CFR of 2.5). RESULTS: The FFR and hESRI had excellent correlation with the r-AS% (group 1: r=0.767, p<0.001; r=0.740, p<0.001; group 2: r=0.680, p=0.004; r=0.713, p=0.002, respectively). Although no significant difference was found in the r-AS% between the two groups, the FFR was significantly lower in group 1 (0.69+/-0.14 vs. 0.79+/-0.10, p=0.004). In group 1, the BCV of the FFR and hESRI for a r-%AS of 75% were 0.75 and 0.64, respectively, and the concordance rates were 86.8% (kappa=0.721, p<0.001) and 81.6% (kappa=0.627, p<0.001), respectively. However, in group 2, the BCV of the FFR and hESRI for an r-%AS of 75% were 0.83 and 0.50, respectively, and the concordance rates were 61.9% (kappa=0.282, p=0.125) and 66.7% (kappa=0.364, p=0.061), respectively. CONCLUSION: The FFR and hESRI were significantly affected by the microvascular integrity of the distal segment of the lesion and the anatomic severity of the coronary stenosis was underestimated in the cases with microvascular dysfunction.

Effect of Distal Protection Device on the Microvascular Integrity during Primary Stenting in Acute Myocardial Infarction: Distal Protection Device in Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: Phasic coronary flow velocity patterns and microvascular integrities are known to be prognostic factors in acute myocardial infarction (AMI). The use of a distal protection device during primary percutaneous coronary intervention (PCI) may preserve the microvascular integrity of the myocardium by preventing distal embolization of thrombotic materials. This study assessed the effects of such a device on microvascular integrity preservation through Doppler studies of the coronary flow velocities in AMI patients treated with primary PCI. SUBJECTS AND METHODS: A total of fifty-eight consecutive patients (mean age 54+/-15, 46 males) with ST segment-elevated AMI, who had undergone primary PCI within 24 hours after onset, were enrolled in the study. The subjects were divided into two groups: 30 patients with the PurcuSurge GuardWire Temporary Occlusion and Aspiration System and 28 without. The TIMI flows and TMP grades (TIMI myocardial perfusion grade) were evaluated. The coronary flow velocities were measured after PCI with a Doppler wire at the baseline, and also after intracoronary adenosine (24-48 microgram) induced hyperemia. The coronary flow velocity reserve (CFR), diastolic deceleration time (DDT) and microvascular resistance index (MVRI) were calculated. RESULTS: Between the two groups, no significant differences were found in the angiographic characteristics and CFR. In patients with a distal protection device, however, the post-PCI TMP grades were more favorable (TMP 0/1: 13.3%, TMP 2: 23.3%, TMP 3: 63.4% vs. TMP 0/1: 35.7%, TMP 2: 35.7%, TMP 3: 28.6%, p=0.023), with TMP grade 3 being most common (63.4% vs. 28.6%, p=0.010). These patients also exhibited lower bMVRI and hMVRI levels (4.33+/-2.22 vs. 5.55+/-2.36 mmHg.m-1.sec (p=0.047) and 2.39+/-1.40 vs. 3.14+/-1.36 mmHg.cm-1. sec (p=0.045), respectively), and longer bDDT and hDDT (679+/-273 vs. 519+/-289 msec (p=0.035) and 761+/-256 vs. 618+/-272 msec (p=0.044), respectively). CONCLUSIONS: Distal protection with the PurcuSurge GuardWire system may effectively preserve the microvascular integrity of the myocardium during primary PCI in AMI patients.

Preprocedural hs-CRP Level Serves as a Marker for Procedure-Related Myocardial Injury During Coronary Stenting

BACKGROUND AND OBJECTIVES: Elevated hs-CRP (high sensitivity C-reactive protein) is well known as a biomarker reflecting the inflammatory process that might evoke the potential for microembolization of an atheromatous plaque, and imparts a poor prognosis in patients with coronary artery disease. We designed this study to evaluate whether the preprocedural hs-CRP level was associated with procedure-related myocardial injury following coronary stenting. SUBJECTS AND METHODS: We obtained the plasma hs-CRP level from angina patient, who underwent coronary stenting, within 24 hours prior to the procedure, and divided the patients into either the normal CRP (hs-CRP or =3 mg/L). We defined the reduction of TMP (TIMI myocardial perfusion) grade as at least one decrease in the TMP grade following coronary stenting compared with the pre-procedural TMP. We also evaluate the procedure-related myocardial damage by measuring CK-MB leakage after stenting. RESULTS: We enrolled 279 lesions in 226 patients, who were divided into two groups: the normal CRP group (n=137, 1.28+/-0.71 mg/L) and the elevated CRP group (n=89, 6.89+/-4.23 mg/L). A reduction in the TMP grade was significantly more prevalent in the elevated CRP (20 lesions, 17.4%) compared to the normal CRP group (6 lesions, 3.7%, p=0.001). An elevated CRP level was related to an increased CK-MB leakage following stenting (elevated CRP group; 23 patients, 25.8%, normal CRP group; 21 patients, 15.3%, p=0.041). In a multivariable analysis, the only significant predictor of a reduction in the TMP grade following stenting was an elevated CRP level. CONCLUSION: Systemically detectable inflammatory activity, served by the plasma hs-CRP level, is associated with procedure-related microvascular injury, as assessed by a reduction in the TMP grade and CK-MB elevation following coronary stenting.

Spontaneous Coronary Artery Dissection Manifested during Ergonovine Test and Treated with Intravascular Ultrasound Guided Stenting: A Case Report

Spontaneous coronary artery dissection (SCAD) is an uncommon cause of acute myocardial ischemia, which frequently presents as sudden death. The pathophysiology and treatment of SCAD have not been fully determined. Herein, a case of SCAD, manifesting as variant angina, which rapidly progressed during an ergonovine test, in which 3 drug-eluting stents were deployed using intravascular an ultrasound guidance, with an excellent immediate result, is reported.

The Effect of Preinfarction Angina as Ischemic Preconditioning on Myocardial Protection

BACKGROUND AND OBJECTIVES: By measuring the coronary flow reserve (CFR) and echocardiographic left ventricular function, the purpose of this study was to evaluate the effect of pre-infarction angina (PA) on myocardial protection in patients with acute myocardial infarction (AMI). SUBJECTS AND METHODS: Sixty-two patients (mean 54+/-10 years, 51 males) with first anterior AMI were studied. CFR, defined as the ratio of hyperemic (hAPV) to baseline APV (bAPV), was measured at least 24 hours after the onset of AMI at the left anterior descending artery (mean 7+/-4 days) with a Doppler wire. Echocardiography was performed at admission (baseline) and during follow-up periods (mean 9+/-7 month). All patients were divided into two groups according to the presence of PA within 72 hours prior to AMI:group A (with PA, n=27) and group B (without PA, n=35). RESULTS: Between the two groups, CFR were higher in group A (2.1+/-0.5 vs.1.6+/-0.5, p<0.001). The baseline left ventricular ejection fraction (LVEF, %) and wall motion score index (WMSI) were better in group A than in B (53.4+/-9.7 vs. 45.1+/-8.8, p=0.001;1.42+/-0.23 vs. 1.72+/-0.28, p<0.001, respectively). LVEF (%) and WMSI during follow-up periods were better in group A than in B (61.3+/-10.2 vs. 54.4+/-13.3, p=0.03;1.24+/-0.21 vs. 1.47+/-0.37, p=0.004, respectively). CONCLUSION: Patients with PA had a significantly higher CFR and better LVF at the baseline and during follow-up periods. This study suggests that brief and repeated myocardial ischemia prior to AMI as ischemic pre-conditioning might have the effect of myocardial protection.