TIMI Myocardial Perfusion Grade Research Articles

Intracoronary ECG during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction predicts microvascular obstruction and infarct size

IntroductionMicrovascular obstruction (MVO) following ST-segment elevation myocardial infarction (STEMI) is associated with larger infarct size and an increased mortality. Although angiographic predictors of MVO in primary percutaneous coronary intervention (primary-PCI) setting have been identified, an earlier and objective “in-lab” predictor may be beneficial, in order to potentially influence therapies administered during primary-PCI. We hypothesised that intracoronary-electrocardiogram (IC-ECG) is a simple, objective and accurate predictor of MVO evaluated by cardiac magnetic resonance (CMR) and is comparable to myocardial blush grade (MBG) and TIMI myocardial perfusion grade (TMPG). MethodIntracoronary ECG was performed during primary-PCI. Intracoronary ST-segment measurement was performed before and immediately after opening of infarct-related-artery. Intracoronary ST-segment resolution (IC-STR) was defined as ≥1mm improvement compared to baseline. Contrast enhanced CMR was performed at 4 and 90days post primary-PCI. Primary endpoint was MVO on late gadolinium hyperenhancement assessed by CMR at day 4. ResultsSixty-four consecutive patients (age 59±11years; 55 males) were recruited. Intracoronary ST-segment resolution correlated with MVO (p=0.005). Furthermore, IC-STR correlated with infarct-mass, non-viable-mass, peak creatinine kinase and end-systolic-volume at day 4. Intracoronary ST-segment resolution also correlated with favourable left ventricular end-diastolic-volume at day 90 (p=0.022). On multivariate analysis, IC-STR was an independent predictor of MVO. ConclusionIntracoronary ST-segment resolution is a strong in-lab predictor of MVO assessed 4days after STEMI on CMR. Furthermore, IC-STR correlates with infarct size and left ventricular remodelling at 3months. Further studies are required to understand potential clinical utility of this tool.

Elevated Serum Uric Acid Predicts Angiographic Impaired Reperfusion and 1-Year Mortality in ST-Segment Elevation Myocardial Infarction Patients Undergoing Percutaneous Coronary Intervention

BackgroundSerum uric acid (SUA) is associated with microvascular disease that could alter coronary blood flow and prognosis. We evaluated the effects of admission SUA levels on coronary blood flow and...

Coronary flow reserve varies depending upon the location within the artery it is assessed and the TIMI myocardial perfusion grade: a PROTECT TIMI-30 analysis

Coronary flow reserve (CFR) is a measure of the capacity of the epicardial coronary artery and the microvasculature to achieve maximal blood flow in response to hyperemic stimulation. It is not known whether the CFR varies along the length of the artery. Likewise, the interaction between CFR and the thrombolysis in myocardial infarction (TIMI) myocardial perfusion grade (TMPG) is unknown. CFR was measured using the number of cineframes required for the contrast to traverse the same length of the coronary artery before and following the administration of intracoronary adenosine. Following percutaneous coronary intervention (PCI), CFR was assessed both proximal and distal to the lesion in 192 consecutive patients with non-ST-segment elevation acute coronary syndrome (NSTEACS) from the PROTECT TIMI-30 trial. TMPG was also assessed. The difference between the distal and proximal CFR for patients with TMPG 0/1 (n=76) was 0.11 (95% CI 0.01-0.20, P=0.026), while among those with TMPG 2/3 (n=114) it was -0.02 (95% CI -0.09-0.06, P=0.65). The difference in the CFR between the distal and proximal segments among patients with TMPG 0/1 and TMPG 2/3 was significant (P interaction=0.044). Following PCI among patients with impaired TMPG (0/1) in the setting of NSTEACS, CFR varies significantly between the proximal and distal segment of coronary arteries and is associated with higher (greater) distal CFR.

Elevated plasma asymmetric dimethylarginine level in acute myocardial infarction patients as a predictor of poor prognosis and angiographic impaired reperfusion

ObjectivesWe aimed to investigate the effects of admission asymmetric dimethylarginine (ADMA) levels on myocardial perfusion and prognosis in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). BackgroundADMA, an endogenous inhibitor of endothelial nitric oxide synthase, was found to be elevated in plasma of patients with cardiovascular risk factors. Methods168 consecutive patients undergoing primary PCI for STEMI <12h after symptom onset and 75 healthy age and sex matched volunteer controls were enrolled in the study. Patients with STEMI were grouped into tertiles according to their admission plasma ADMA levels. Major adverse cardiac events during hospitalization or at one-year clinical follow-up were evaluated. Also angiographic impaired reperfusion was assessed by 3 different methods after PCI: angiographic thrombolysis in myocardial infarction (TIMI) flow, TIMI frame count and TIMI myocardial perfusion grade (TMPG). ResultsPlasma level of l-arginine were lower in patients with STEMI than in the control group subjects, whereas plasma ADMA levels were increased in the STEMI patient group. The rate of impaired angiographic reperfusion increased across the tertile groups. Also one-year mortality rates showed a significant increase across the tertile groups (4% vs. 10% vs. 20%, p<0.01). Using multiple Cox regression analysis, only TIMI risk score, left ventricle ejection fraction (LVEF), abnormal TMPG, and increased ADMA values on admission emerged as independent predictors of one-year mortality. The ROC analysis indicated an optimal cut-point of ≥1.37μmol/L, which detects one-year mortality with a negative predictive value of 96%. ConclusionsIn STEMI patients undergoing primary PCI, high admission ADMA levels were found to be associated with impaired myocardial perfusion and increased one-year mortality. Therefore admission ADMA level detection may be helpful in identifying the patients at a greater risk of impaired myocardial perfusion and poor prognosis.

Circulating CD34+ progenitor cells and growth factors in patients treated with PCI for acute myocardial infarction or stable angina pectoris

Objective. To differentiate the effect of myocardial infarction from the effect of percutaneous coronary intervention (PCI) on the circulatory profiles of CD34+ cells and growth factors in patients with ST-elevation myocardial infarction (STEMI). Methods. Twenty patients with STEMI and 10 with angina pectoris (AP) were included. All were treated with PCI. Blood was drawn before PCI in the AP group, and after 3 and 12 hours, and 1, 3, 5, 7 and 14 days after PCI in both groups. In STEMI patients, correlation analyses between TIMI myocardial perfusion grade (TMP-grade) and circulating CD34+cells were also assessed. Results. Circulating CD34+ cells increased from day 1 to days 5 and 7 after PCI only in STEMI patients (p < 0.05). Between-group analyses revealed a borderline significant difference in change in SDF-1α concentrations from 3 h to 14 days after PCI (p = 0.05), and SDF-1α was significantly higher in STEMI patients 14 days after PCI (p < 0.05). In both groups, peak HGF concentrations were observed 3 h after PCI, whereas IGF-1 increased in AP patients only, 3 h after PCI (p < 0.005). TIMI perfusion grade was negatively correlated to the circulating number of CD34+ cells 5 days after PCI (r =−0.69, p < 0.005). Conclusion. After PCI, STEMI patients have significantly higher numbers of circulating CD34+ progenitor cells compared to patients with AP. STEMI results in a significant increase in SDF-1α after 14 days, and the increase at this time may indicate a favorable environment for progenitor cell therapy.

Investigation of the mechanism of reverse redistribution in thallium-201 myocardial perfusion scintigraphy in patients with suspicion for coronary artery spasm

BackgroundReverse redistribution (RR) is one of the features on myocardial perfusion scintigraphy (MPS) in patients with coronary artery spasm (CAS). This study was aimed to explore the mechanism of RR in patients with suspicion for CAS. Methods and ResultsThirty patients with RR and suspicion for CAS but without coronary artery stenosis (RR group) and 32 control patients without RR (control group) underwent coronary angiography before and after a dipyridamole administration. Coronary blood flow velocity and myocardial perfusion, as determined by corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and TIMI myocardial perfusion grade (TMPG), were measured. Coronary angiography showed significantly slower blood flow velocity [CTFC (37 ± 6) frame vs (29 ± 7) frame, P < .01] and lower myocardial perfusion [TMPG (2.08 ± 0.38) grade vs (2.55 ± 0.33) grade, P < .05] in RR-related arteries than in RR-unrelated arteries in the RR group. But, there was no significant difference among different coronary artery branches in the control group. After the injection of dipyridamole, CTFC decreased and TMPG increased in the RR group. The decline in CTFC and the increase in TMPG in RR-related arteries were more significant than those in RR-unrelated ones (28% vs 14% and 45% vs 16%, respectively; both P < .01). The endothelin-1/nitric oxide (NO) ratio was significantly higher in the RR group than in the control group before the injection of dipyridamole (2.79 ± 0.37 vs 1.70 ± 0.19, P < .01). After the injection of dipyridamole, the ratio went down in both groups, but the decline was statistically significant in the RR group (2.42 ± 0.33, P < .05) but not in the control group (1.42 ± 0.19, P < .05). Pearson correlation analysis showed that there was a positive correlation between summed rest scores on MPS and the endothelin-1/NO ratio (r = 0.853, P = .000) as well as CTFC (r = 0.808, P = .000) before the injection of dipyridamole in the RR group. ConclusionPatients with suspicion for CAS may exhibit a mild spasm of RR-related arteries and corresponding microvasculature and a significant imbalance of coronary blood flow velocity and myocardial perfusion at rest between RR-related and RR-unrelated areas. This is overcome by stress-induced hyperemic flow increases and which may account for RR on MPS.

Effect of Aspiration Thrombectomy on Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction With an Elevated Neutrophil Count

Background and ObjectivesAspiration thrombectomy (AT) during primary percutaneous coronary intervention (PCI) is an effective adjunctive therapy for ST-segment elevation myocardial infarction (STEMI). An elevated neutrophil count in STEMI is associated with microvascular dysfunction and adverse outcomes. We evaluated whether AT can improve microvascular dysfunction in patients with STEMI and an elevated neutrophil count.Subjects and MethodsSeventy patients with STEMI undergoing primary PCI from August 2007 to February 2009 in our institution were classified by tertiles of neutrophil count on admission (<5,300/mm3, 5,300-7,600/mm3, and >7,600/mm3). The angiographic outcome was post-procedural thrombolysis in myocardial infarction (TIMI) flow grade. Microvascular dysfunction was assessed by TIMI myocardial perfusion (TMP) grade and ST-segment resolution on electrocardiography 90 minutes after PCI. The clinical outcome was major adverse cardiac event (MACE), defined as cardiac death, re-infarction, and target lesion revascularization at 9 months.ResultsThere were no significant differences in the clinical characteristics and pre- and post-procedural TIMI flow grades between the neutrophil tertiles. As the neutrophil count increased, a lower tendency toward TMP grade 3 (83% vs. 52% vs. 54%, p=0.06) and more persistent residual ST-segment elevation (>4 mm: 13% vs. 26% vs. 58%, p=0.005) was observed. The 9-month MACE rate was similar between the groups. On subgroup analysis of AT patients (n=52) classified by neutrophil tertiles, the same tendency toward less frequent TMP grade 3 (77% vs. 56% vs. 47%, p=0.06) and persistent residual ST-segment elevation (>4 mm: 12% vs. 28% vs. 53%, p=0.05) was observed as neutrophil count increased.ConclusionA higher neutrophil count at presentation in STEMI is associated with more severe microvascular dysfunction after primary PCI, which is not improved with AT.

Gender differences in epicardial and tissue-level reperfusion in patients undergoing primary angioplasty for acute myocardial infarction

ObjectiveThe impact of gender on clinical course after ST-elevation myocardial infarction (STEMI) is not fully understood. We prospectively investigated whether there are gender-related differences in epicardial and myocardial tissue-level perfusion, both of which represent important prognotic determinants in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). MethodsA total of 594 consecutive non-selected STEMI patients undergoing PPCI were prospectively enrolled. Primary end-point of the study was post-procedural epicardial and myocardial perfusion. Secondary end-points were the 30-day and 6-month composite occurrence of major adverse cardiac events (MACE). ResultsWomen with STEMI had higher risk factor profiles than men. Although PPCI achieved equal rates of successful epicardial reperfusion, women tended to have impaired microvascular reperfusion as reflected by lower rates of normal TIMI myocardial perfusion grade (P=0.007) and complete ST-segment resolution (P=0.079). After adjustment for the risk profiles, multivariable analysis showed that gender itself was not an independent predictor of impaired microvascular reperfusion. Both female gender and impaired myocardial reperfusion were independent predictors of 30-day MACE, whereas gender lost its prognostic significance for 6-month MACE. Multivariable analysis restricted to female patients identified incomplete ST-segment resolution as the strongest determinant of 30-day MACE. ConclusionThe differences in microvascular reperfusion after PPCI between women and men are attributed to higher risk profiles in women. Both female gender and impaired myocardial reperfusion were independent predictors of 30-day outcomes after PPCI, emphasizing the importance of successful microvascular reperfusion in the women with STEMI.

E0654 The effect of preventive intracoronary administration of anisodamine on microcirculation perfusion in miniswines with AMI

ObjectiveAnisodamine is a M-cholinergic receptor inhibitor that plays improvement effectiveness on the microcirculative perfusion. Our previous study had ever shown reversing effect on no-reflow phenomenon (NRP) in the miniswine models...

E0298 Intensive cholesterol lowering with simvastatin improves outcomes of percutaneous coronary intervention in patients with acute coronary syndrome

ObjectiveTo evaluate the immediate protective effects of intensive statin pretreatment on myocardial perfusion and myocardial ischaemic injury during PCI.MethodsA total of 228 acute coronary syndrome (ACS) patients were randomly divided...

E0524 Intensive cholesterol lowering with simvastatin improves the outcomes of percutaneous coronary intervention in patients with acute coronary syndrome

ObjectiveTo evaluate the immediate protective effects of intensive statin pretreatment on myocardial perfusion and myocardial ischaemic injury during PCI.MethodsA total of 228 acute coronary syndrome (ACS) patients were randomly divided...

E0540 Efficacy and safety of tirofiban-assisted Delayed PCI in Patients with ST-segment elavation myocardial infarction

ObjectiveTo compare the outcomes of IIb/IIIa antagonist assisted PCI within 12–72 h of onset with that of selective PCI within 7–10 days in STEMI patients.MethodsTotally, 80 patients were randomly allocated...

E0455 Effect on left ventricular function and safety of high maintenance dose of clopidogrel in patients with acute anterior myocardial infarction undergoing selective PCI

ObjectiveTo assess the beneficial efficacy and safety of the high maintenance dose of clopidogrel in acute anterior myocardial infarction (AMI) patients undergoing selective percutaneous coronary intervention (PCI).Methods25 patients were enrolled...

E0633 The effect on Left Ventricular Function and Safety of High Maintenance Dose of Clopidogrel in Patients with Acute Anterior Myocardial Infarction Undergoing Selective PCI

ObjectiveTo assess the beneficial efficacy and safety of the high maintenance dose of clopidogrel in acute anterior myocardial infarction (AMI) patients undergoing selective percutaneous coronary intervention (PCI).MethodsFifty two patients were...

E0161 Establishment of minipig model of ischaemic heart failure with acute myocardial infarction by coronary occlusion with balloon occluding and intermixture injecting of microthrombi and plastic microspheres

ObjectiveTo evaluate the of method of minipig model of ischaemic heart failure (HF) with acute myocardial infarction (AMI) by coronary occlusion with balloon occluding and coadministration injecting of microthrombi and...

Dipyridamole versus verapamil for treatment of no‐reflow during primary angioplasty

No previous study has assessed the possible role of dipyridamole for treatment of no-reflow during acute myocardial infarction (AMI). Forty-six consecutive patients (age 64 ± 13 years, 37 men) with no reflow during primary percutaneous coronary intervention were randomized to initial treatment with either dipyridamole (0.56 mg/kg i.c.) or verapamil (1 mg i.c.). Patients with unsuccessful response to the first drug were then switched to the second one (from dipyridamole to verapamil and vice versa). Angiographic end-points were similar in the two groups: TIMI flow was 2.9 ± 0.3 versus 2.8 ± 0.4 (P = 0.28), corrected TIMI frame count (cTFC) 26.4 ± 8.8 versus 31.6 ± 11.4 (P = 0.14) and TIMI myocardial perfusion grade (TMPG) 2.1 ± 1.2 versus 1.7 ± 1.2 (P = 0.12) in dipydidamole and verapamil group, respectively. Optimal myocardial perfusion (TMPG-3) was achieved by 56% of patients with dipyridamole and 39% with verapamil (P = 0.38). In patients with persistent no-reflow administration of dipyridamole on top of verapamil resulted in a significant further improvement of cTFC (from 31.6 ± 11.4 to 24.6 ± 5.7 P = 0.009) and of TMPG (from 1.7 ± 1.2 to 2.6 ± 0.7, P = 0.007). Conversely, verapamil did not induce a significant improvement in coronary flow (cTFC changed from 26.4 ± 8.8 to 24.5 ± 8.5, P = 0.28 and TMPG from 2.1 ± 1.2 to 2.4 ± 1.2, P = 0.13). There were no significant side effects induced by dipyridamole, while verapamil caused AV block in 9% of cases. Dipyridamole is a safe and effective first-line drug for treatment of no-reflow. Dipyridamole can also be successfully used in patients with incomplete response to verapamil.

Comparison of epicardial and myocardial perfusions after primary coronary angioplasty for ST-elevation myocardial infarction in patients under and over 75 years of age

Patients aged ≥75 years compose a high-risk subgroup for acute myocardial infarction (AMI). It is unknown whether myocardial perfusion in these patients is decreased compared with younger ones after primary percutaneous coronary intervention (PPCI), which may contribute to their worse prognosis. We compared epicardial and myocardial perfusions as well as short-term outcomes between elderly and younger patients undergoing PPCI. A total of 547 consecutive PPCI patients were prospectively enrolled; of these, 106 were elderly (≥75 yrs). Epicardial perfusion was evaluated by the Thrombolysis in Myocardial Infarction (TIMI) flow grade and corrected TIMI frame count (CTFC), and myocardial perfusion was evaluated by the TIMI myocardial perfusion grade (TMPG) and ST-segment resolution (STR). Despite comparable epicardial perfusion pre- and post-PPCI, elderly patients had impaired myocardial perfusion after PPCI, as measured by reduced TMPG (35.9% vs 14.5%, p=0.001) and absent STR (18.9% vs 9.8%, p=0.009). After adjusting for clinical and angiographic risk profiles, multivariate analysis showed that age ≥75 years remained independently associated with reduced TMPG or absent STR. In the whole population, multivariate analysis revealed that both age ≥75 years and absent STR were independently associated with 3-month major adverse cardiac events (MACE). In the elderly subgroup, multivariate analysis identified absent STR as the strongest determinant of 3-month MACE. Age is associated with impaired myocardial perfusion, but not epicardial perfusion, after PPCI for AMI. To further improve the outcome of elderly AMI patients, efforts should be aimed at improving myocardial perfusion beyond epicardial recanalization.

Long-term Outcome of Tako-tsubo Cardiomyopathy

Current data suggest an excellent outcome for patients with Tako-tsubo cardiomyopathy (TC). The objectives of this study were to evaluate the long-term outcome and the prognostic implication of thrombolysis in myocardial infarction myocardial perfusion grade (TMPG) in patients with TC. Retrospective analysis of all patients diagnosed with TC at our hospital between 2003 and 2008. During the five-year period, we identified 27 patients with TC out of 1374 cases of emergent left heart catheterisation (2%). Mean follow-up was 27 ± 16 months. The majority were Caucasian (81%) female (96%), postmenopausal (96%), with a mean age of 68 ± 14 years. A precipitating stressor event was found in 74% of the patients, 30% being gastrointestinal triggers. Fourteen patients (52%) reached a combined end point of all cause death, cardiogenic shock, sudden cardiac death and rehospitalisation for cardiac reasons. TMPG was abnormal in 37% cases with no correlation with the outcome. The long-term outcome of patients with TC is worse than previously reported. TMPG does not correlate with the outcome in TC.

Rationale and Design of the POSTEMI (Postconditioning in ST-Elevation Myocardial Infarction) Study

Rapid reperfusion of the infarct-related coronary artery is essential in the treatment of acute ST-elevation myocardial infarction (STEMI). Paradoxically, restoration of the blood flow to the ischemic area may result in further injury to the myocardium. This phenomenon is described as ‘ischemia/reperfusion injury’ and the pathophysiological mechanisms are not fully elucidated. A cardioprotective effect of ischemic postconditioning (short repetitive cycles of reperfusion and re-occlusion) has been demonstrated in experimental studies and in pilot studies on patients with acute STEMI treated with primary percutaneous coronary intervention. We present the study design of the Postconditioning in ST-Elevation Myocardial Infarction (POSTEMI) study, which is a prospective, randomized, open-label clinical trial with blinded endpoint evaluation designed to evaluate the effect of postconditioning on final infarct size. Patients with acute STEMI with symptoms of less than 6 h and proximal or mid-coronary artery occlusion will be included. The primary endpoint is infarct size, assessed by cardiac MRI after 4 months. The secondary endpoints are to evaluate the effect of postconditioning on TIMI myocardial perfusion grade, resolution of ST-segment elevation, release of markers of ischemia, left ventricular function and final infarct size related to the area at risk. A total of 260 patients will be included in the study.

Angiographic perfusion score assessed in patients with acute myocardial infarction is correlated with cardiac magnetic resonance infarct size and N-terminal pro-brain natriuretic peptide in 6-month follow-up

Angiographic Perfusion Score (APS) proposed as a simple, angiographic score linking epicardial and myocardial perfusion parameters before and after percutaneous coronary intervention (PCI) is a predictor of short-term outcome in patients with ST-segment elevation myocardial infarction (STEMI) treated with PCI. Aim of the study was to analyze the correlation between APS and both infarct size and left ventricular function in long-term follow-up. In a cohort of 68 patients with STEMI treated with PCI APS was calculated for infarct-related artery based on angiographic parameters and was defined as the sum of the Thrombolysis in Myocardial Infarction (TIMI) flow grade (0-3 points) and the TIMI myocardial perfusion grade (0-3 points) before and after PCI (range of points from 0 to 12). Full perfusion was defined as APS ≥ 10. Cardiac magnetic resonance (CMR) parameters and N-terminal pro-brain natriuretic peptide (NT pro-BNP) were assessed at 6 months. Median APS was 7.5 points. APS ≥ 10 was present in 42% of patients. The significant correlation was found between APS and: CMR infarct size (r = - 0.48; P = 0.0001), CMR left ventricular (LV) ejection fraction (r = 0.5; P = 0.002), LV end-diastolic volume index (r = - 0.37; P = 0.004), LV end-systolic volume index (r = -0.41; P = 0.001), NT pro-BNP (r = - 0.5; P = 0.02). Patients with APS ≥ 10 had significantly lower infarct size, LV volumes, higher EF and lower NT pro-BNP. APS assessed in patients with STEMI treated with PCI is a good predictor of infarct size and left ventricular function in 6-month follow-up.