ST-segment Recovery Research Articles

Intracoronary ECG ST‐segment recovery during primary percutaneous intervention for ST‐segment myocardial infarction: Insights from a cardiac MRI study

ST-segment-resolution (STR) on surface electrocardiogram (ECG) is a good surrogate for myocardial reperfusion in patients with acute ST-segment-elevation-myocardial-infarction (STEMI). We sort to determine the optimal criteria of measuring STR on intracoronary-ECG (IC-ECG) for prediction of myocardial injury evaluated by cardiac MRI (CMR). Measurements of IC-ECG ST-segments were performed at baseline, immediately after (early) and 15 min (late) after achieving TIMI-3 flow during primary-PCI. The degree of ST-segment-shift from baseline noted upon the IC-ECG was divided into four groups: (group 1) ST-segment-resolution >1 mm, (group 2) <30% resolution, (group 3) >50% resolution, (group 4) >70% resolution at both early and late time points. Patients had CMR at days 3 and 90 postprimary-PCI. Fifty two patients (aged 60 ± 11 years; 43 males) were evaluated. Early intracoronary-ECG ST-segment resolution (early IC-STR >1 mm) correlated with smaller scar mass (P = 0.003), nonviable myocardial mass (P < 0.001), and microvascular obstruction (MVO) (P = 0.004) on CMR at day 3. Ejection fraction (EF) was also better at day 3 (P = 0.026) and 90 (P = 0.039). Patients with poor early IC-STR (IC-STR <30%) conversely is associated with larger scar mass (P = 0.017), nonviable myocardial mass (P = 0.01), and MVO (P = 0.021) at day 3. This was also associated with worse EF at day 90 (P = 0.044). Neither group 3 or 4, or the late measurements of late IC-STR correlated with CMR markers of myocardial injury. The degree of early IC-STR (defined by IC-STR > 1 mm or <30%) successfully predicts myocardial damage following primary-PCI for an acute STEMI. Further studies are required to investigate its potential utility.

The relationships between cardiovascular magnetic resonance imaging variables of acute myocardial infarction and both left ventricular dysfunction and immediate postreperfusion ST segment recovery

Objective The aim of this study is to explore the relationships between cardiovascular magnetic resonance imaging (CMR)–determined variables of acute myocardial infarction and both left ventricular (LV) dysfunction and immediate postreperfusion ST segment recovery. Methods In 79 patients with first acute myocardial infarction, 8 different ST segment recovery (STR) variables were measured 30 and 60 minutes after percutaneous coronary intervention. Cardiovascular magnetic resonance imaging was performed 5 ± 2 and 104 ± 11 days after admission. Using k-means cluster analysis, 3 CMR risk groups for LV dysfunction (low LV ejection fraction at baseline and follow-up) were identified based on combinations of infarct size (IS), infarct transmurality, and microvascular obstruction. Stepwise discriminant analysis was used to determine which STR variable best discriminated between CMR risk groups. Results Baseline LV ejection fraction improved in all groups but remained lowest in the high-risk group (41% ± 7% and 44% ± 6%), as compared with the intermediate (51% ± 5% and 56% ± 5%) and low-risk groups (56% ± 7% and 58% ± 5%). Infarct size was significantly different among the groups (34% ± 5%, 19% ± 4%, and 6% ± 4%; P < .001) and mainly determined the effect on LV dysfunction. Of all STR variables, worst lead residual ST deviation 30 minutes after reperfusion accurately discriminated between the high- and combined low-/intermediate risk groups. Conclusion Worst lead residual ST deviation 30 minutes after reperfusion allows accurate identification of patients at high risk for LV dysfunction, which was mainly related to IS rather than transmurality or microvascular obstruction.

Histopathology of aspirated thrombus and its association with ST‐segment recovery in patients undergoing primary percutaneous coronary intervention with routine thrombus aspiration

In patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) with thrombus aspiration, the histopathology of aspirated thrombus was previously related to long-term mortality. In this study, we sought to investigate the association between histopathology of aspirated thrombus and ST-segment recovery, a marker of microvascular dysfunction, immediately at the end of the PCI procedure. We included 892 STEMI patients who underwent primary PCI with routine thrombus aspiration and for whom combined data on histopathology of aspirated thrombus and ST-segment recovery were available. Patients were categorized according to histopathology of aspirated thrombus: fresh only (<1 day), older (>1 day), or no material aspirated. ST-segment recovery was defined as incomplete if <50%. Incomplete ST-segment recovery occurred in 134 of 363 patients (37%) with fresh thrombus, in 104 of 238 patients (44%) with older thrombus, and in 142 of 291 patients (49%) with no material. Unadjusted odds ratios for incomplete ST-segment recovery of patients with older thrombus and no material, when compared with patients with fresh thrombus, were 1.33 (95% CI, 0.95-1.85; P = 0.097) and 1.63 (95% CI 1.19-2.23; P = 0.002), respectively. Both associations were unchanged after multivariable adjustment for clinical predictors of ST-segment recovery. ST-segment recovery was a strong predictor of long-term mortality, independent of the histopathology of aspirated thrombus. This study shows that ST-segment recovery immediately at the end of the PCI procedure was a significant prognosticator, independent of the histopathology of aspirated thrombus. We found that the histopathology of aspirated thrombus (fresh, older, no material) was associated with ST-segment recovery in STEMI patients undergoing primary PCI with thrombus aspiration.

Prediction of 1-Year Mortality With Different Measures of ST-Segment Recovery in All-Comers After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

Post hoc analyses from several randomized, controlled trials have established the prognostic importance of different measures of ST-segment recovery in highly selected patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment-elevation myocardial infarction (STEMI). In this single-center registry, we investigated whether various measures of ST-segment recovery can be applied to unselected STEMI patients undergoing primary PCI. We analyzed 12-lead ECGs from 2124 consecutive STEMI patients who underwent primary PCI at our institution between November 1, 2000, and January 1, 2007. ECGs were recorded at the catheterization laboratory immediately before arterial puncture and at the end of PCI. We examined measures assessing ST-segment recovery on the postprocedural ECG and measures comparing both ECGs and related these to 1-year, all-cause mortality. Cumulative ST-segment recovery (∑ST-D resolution) at a 50% cutoff had the highest unadjusted accuracy (C statistic, 0.646; 95% confidence interval, 0.602 to 0.689; P<0.001) as compared with the other 8 measures evaluated. Furthermore, ∑ST-D resolution was the strongest contributor to both the net reclassification and integrated discrimination improvement. Although each measure of ST-segment recovery provided univariable prognostic information, the ∑ST-D resolution measure comparing summed ST-segment deviations on the preprocedural and postprocedural ECG was the best independent predictor of 1-year mortality in all-comer STEMI patients after primary PCI.

Analysis of the factor of effective thrombus aspiration on patients in primary percutaneous coronary intervention

Objective To find the factors lowering the rate of effective thrombus aspiration in patients with STsegment elevation acute myocardial infarction (STEMI) treated with primary percutaneous coronary intervention(PCI). Method From January to December 2008 , a total of 226 AMI patients from Beijing Anzhen Hospital,treated with primary PCI to aspirate the thrombus from the infracted coronary artery via a cannula, were enrolled in a single center retrospective study. The criterion of successful thrombectomy (device success) was defined as the coronary blood flow of involved vessel after PCI resumed to greater than TIMI grade 1. One hundred seventy-eight patients were assigned to effective thrombus aspiration group, and 48 patients without improvement in coronary blood flow of involved vessel after PCI to control group. Data collected after PCI including the normalization of the elevated ST segment,the use of direct stent, ratio of no-flow/slow flow, intra-coronary administration of Tirofiban and the rate of thrombolysis in myocardial infarction (TIMI) flow grade 3 were analyzed with logistic analysis soas to find out the factors affecting the efficacy of thrombus aspiration. Results There were no significant differences in data before PCI between two groups ( P ＞0.05). Compared with the control group, the factors studied such as smoke, diabetes, the rate of pre-PCI TIMI flow grade 0,the post-PCI ratio of no-reflow/slow flow,and the intra-coronary administration of Tirofiban were fewer significantly in the effective thrombus aspiration group. And the rate of post-PCI TIMI flow grade 3, and the rate of direct stent were higher in the effective thrombus aspiration group. Logistic analysis showed that smoke ( OR = 1.551,95%CI: 1.018 ～ 2. 154, P = 0.012), diabetes ( OR = 1. 132,95%CI:0.276 ～ 3.562, P =0.044), and pre-PCI TIMI flow grade 0 OR = 0.544,95%CI:0.368 ～ 1.911,P = 0.035) were independent factors of effective thrombus aspiration. Conclusions Effective thrombus aspiration may improved the coronary blood flow to TIMI flow grade 3 after PCI and reduce the impaiment of myocardial perfusion, and the factors affecting the efficacy of thrombus aspiration should be paid more attention to and should be minimized to achieve the better clinical outcomes. Key words: Acute myocardial infarction; Primary percutaneous coronary intervention; Thrombus aspiratiou; Effective; ST segment recovery; Direct stem; No-reflow/slow flow; Effect factors

Early ST-segment recovery after primary percutaneous coronary intervention accurately predicts long-term prognosis after acute myocardial infarction

Several ancillary studies reported on the prognostic value of ST-segment recovery (STR) with measurement at 30 to 240 minutes after primary percutaneous coronary intervention (PCI). We determined the long-term prognostic value of early STR, assessed at the end of primary PCI, in unselected patients after ST-segment elevation myocardial infarction (STEMI). We analyzed 12-lead electrocardiograms, recorded in the catheterization laboratory before arterial puncture and at the time of the end of PCI, from 2,124 STEMI patients who underwent primary PCI at our institution between 2000 and 2007. ST-segment recovery was categorized as complete (> or =70%), partial (30%-70%), or absent (<30%). Median follow-up was 4.1 years. The estimated 5-year mortality was 8.3% in patients with complete STR, 14.4% in patients with partial STR, and 22.8% in patients with absent STR (P < .001). Multivariable-adjusted hazard ratios for 1-year death of patients with partial and absent STR, as compared with patients with complete STR, were 2.1 (95% CI 1.2-3.8, P = .014) and 3.2 (95% CI 1.8-5.8, P < .001), respectively. In a landmark analysis restricted to 1-year survivors, early STR was significantly predictive of 5-year mortality, even after multivariable adjustment. Early STR assessment has strong, long-term prognostic properties in all-comer STEMI patients. Moreover, the prognostic power of early STR is not restricted to the early recovery phase after STEMI, but identifies high-risk subgroups among 1-year survivors.

Time to Stable ST-Segment Recovery Following Primary Angioplasty is Predictive of Regional Wall Motion Score and Clinical Outcome

We report the time to stable ST-segment reperfusion (TSTR) after primary angioplasty and its relationship with the clinical results; 137 patients who underwent primary angioplasty were included as part of the analysis. All patients had 24 hours ST-segment monitoring. Time to stable STR was defined as the beginning of ST-segment reperfusion (STR) lasting >4 hours without ST-segment reelevation. Six-month mortality was associated with slower TSTR (median 166.5 vs 6 minute, P = .001). Time to stable STR cutoff value of 136.5 minutes was identified as the best mortality predictor (area under the curve: 0.86, P = .001). Multivariate analysis identified Killip class > or = 2 (P = .042), TSTR cutoff value (P = .002), and final thrombolysis myocardial infarction (TIMI) flow grade III (P = .067) as predictors of 6-month mortality. Time to stable STR may be a novel continuous electrocardiogram (ECG) parameter following primary angioplasty, which can identify high-risk patients that need to be considered for additional treatments.

Clinical and Angiographic Predictors of ST-Segment Recovery After Primary Percutaneous Coronary Intervention

Important determinants of incomplete ST-segment recovery in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) have been incompletely characterized. Early risk stratification could identify patients with STEMI and incomplete ST-segment recovery who may benefit from adjunctive therapy. For the present study, we analyzed 12-lead electrocardiograms from 2,124 patients with STEMI who underwent primary PCI at our institution from 2000 to 2007. ST-segment recovery was defined as percent change in cumulative ST-segment deviation between preprocedural and immediately postprocedural electrocardiograms and categorized as incomplete when <50%. A total of 1,032 patients (49%) had incomplete ST-segment recovery. After multivariable adjustment, age >60 years (adjusted odds ratio [OR] 1.28, 95% confidence interval [CI] 1.06 to 1.54, p = 0.011), diabetes mellitus (OR 1.36, 95% CI 1.02 to 1.82, p = 0.034), left anterior descending coronary artery-related STEMI (OR 1.92, 95% CI 1.61 to 2.30, p<0.001), and multivessel disease (OR 1.34, 95% CI 1.10 to 1.63, p = 0.004) were independent predictors of incomplete ST-segment recovery. Current smoking (OR 0.79, 95% CI 0.65 to 0.95, p = 0.013) and a preprocedural Thrombolysis In Myocardial Infarction grade <3 flow (OR 0.70, 95% CI 0.53 to 0.93, p = 0.014) were inversely related to ST-segment recovery. Incomplete ST-segment recovery was a strong predictor of long-term mortality (hazard ratio 2.07, 95% CI 1.59 to 2.69, p <0.001) in addition to identified characteristics that independently predicted incomplete ST-segment recovery. In conclusion, incomplete ST-segment recovery at the end of PCI occurred significantly more often in the presence of an age >60 years, nonsmoking, diabetes mellitus, left anterior descending coronary artery-related STEMI, multivessel disease, and preprocedural Thrombolysis In Myocardial Infarction grade 3 flow. Patients with STEMI and these clinical features are at increased risk of impaired myocardial salvage and are appropriate candidates for adjunctive therapy.

Influence of ST-Segment Recovery on Infarct Size and Ejection Fraction in Patients With ST-Segment Elevation Myocardial Infarction Receiving Primary Percutaneous Coronary Intervention

In patients with ST-segment elevation myocardial infarction treated with fibrinolytics, electrocardiogram-derived measures of ST-segment recovery guide therapy decisions and predict infarct size. The comprehension of these relationships in patients undergoing mechanical reperfusion is limited. We studied 144 patients treated with primary percutaneous coronary intervention. We aimed to define the association between infarct size as determined by cardiac magnetic resonance imaging and different metrics of ST-segment recovery. Electrocardiograms were assessed at baseline and 90 minutes after primary percutaneous coronary intervention. Three methods for calculating and categorizing ST-segment recovery were used: (1) summed ST-segment deviation (STD) resolution analyzed in 3 categories (> or = 70%, > or = 30% to <70%, and <30%); (2) single-lead STD resolution analyzed in the same 3 categories; (3) worst-lead residual STD analyzed in 3 categories (<1 mm, 1 to <2 mm, and > or = 2 mm). Infarct size and ejection fraction were assessed at 4 months by cardiac magnetic resonance imaging. All 3 ST-segment recovery algorithms predicted the final infarct size and cardiac function. Worst-lead residual STD performed the same as, or better than, the more complex methods and identified large subgroups at either end of the risk spectrum (median infarct size from the lowest to highest risk category (percentage of left ventricle: 7.7% [interquartile range 10.8], 13.1% [interquartile range 13.6]; 24.6% [interquartile range 21.1]); with adjusted odds ratios for infarct size greater than the median (reference <1 mm): 1 to <2 mm, odds ratio 2.3 (95% confidence interval 0.8 to 5.9); > or = 2 mm, odds ratio 6.3 (95% confidence interval 1.7 to 23.7; c-index 0.781). In conclusion, an electrocardiogram obtained early after primary percutaneous coronary intervention analyzed by a simple algorithm provided prognostic information on the final infarct size and cardiac function.

Comparison of the Usefulness of N-Terminal Pro-Brain Natriuretic Peptide to Other Serum Biomarkers as an Early Predictor of ST-Segment Recovery After Primary Percutaneous Coronary Intervention

Data on the ability of serum biomarkers to predict microvascular obstruction by ST-segment recovery after primary percutaneous coronary intervention (PCI) is largely absent. Therefore, we determined the association between 5 serum biomarkers, obtained before emergency coronary angiography, and immediate ST-segment recovery in patients who had undergone primary PCI for ST-segment elevation myocardial infarction. We measured N-terminal pro-brain natriuretic peptide (NT-pro-BNP), cardiac troponin T, creatinine kinase-MB fraction, high-sensitivity C-reactive protein, and serum creatinine from blood samples obtained through the arterial sheath at the start of primary PCI. Serial 12-lead electrocardiograms were recorded in the catheterization laboratory before arterial puncture and at the end of the PCI. ST-segment recovery was defined as incomplete if <50%. Of 662 included patients with ST-segment elevation myocardial infarction, 338 (51%) had incomplete ST-segment recovery. An elevated NT-pro-BNP level (> or = 608 ng/L) was the strongest predictor of incomplete ST-segment recovery (adjusted odds ratio 2.6, 95% confidence interval 1.6 to 4.1; p <0.001) compared to other serum biomarkers and clinical predictors. An elevated NT-pro-BNP level was more strongly predictive in patients without a history of coronary artery disease or hypertension (adjusted odds ratio 4.7, 95% confidence interval 2.4 to 9.2; p <0.001). NT-pro-BNP was the best contributor to both net reclassification (0.43; p <0.001) and integrated discrimination improvement (0.04; p <0.001) when added to a multivariate model with clinical predictors of incomplete ST-segment recovery. In conclusion, NT-pro-BNP was the strongest independent predictor of ST-segment recovery at the end of primary PCI for ST-segment elevation myocardial infarction compared to the other serum biomarkers reflecting myocardial cell damage, renal function, and inflammation.

TCT-319: Expanding the Smoker's Paradox: Smoking is Associated with Significantly Better ST-Segment Recovery and Survival In Patients with Acute Myocardial Infarction Undergoing Primary Angioplasty

TCT-319: Expanding the Smoker's Paradox: Smoking is Associated with Significantly Better ST-Segment Recovery and Survival In Patients with Acute Myocardial Infarction Undergoing Primary Angioplasty

TCT-6: ST-Segment Recovery at Last Contrast Injection Accurately Predicts Five-Year Mortality in Patients After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

TCT-6: ST-Segment Recovery at Last Contrast Injection Accurately Predicts Five-Year Mortality in Patients After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

Immediate versus delayed angioplasty in infarct-related arteries with TIMI III flow and ST segment recovery: a matched comparison in acute myocardial infarction patients

Early management of patients with patent infarct-related artery (IRA) and optimal ST resolution in ST elevation myocardial infarction (STEMI) has never been assessed. We compared immediate vs delayed PCI in these patients. Matched comparison of immediate vs delayed (24 h) PCI in STEMI patients presenting with patent IRA, thrombus-containing lesion and ST resolution >or=70%. Patients were matched for duration of symptoms, intervention type, angiographic data, diabetes. Patients in immediate PCI group received standard therapy in the cathlab. Patients in delayed PCI group received dual antiplatelet therapy, antithrombins, and GPIIb-IIIa inhibitors until PCI. Primary endpoint was procedural success. Secondary endpoints were enzyme release and in-hospital adverse events. Seventy-eight patients were included: 39 per group. Average age 62 years, 75% males. There was a significantly higher procedural success rate in the delayed PCI group (95% success, Vs. 77% in the immediate group, P = 0.008). Initial thrombus burden score did not differ between immediate and delayed PCI groups, but improved significantly in the delayed group between baseline angiography and time of PCI (P = 0.039). There was no difference in major adverse events or bleeding complications between groups. Peak CK levels were significantly higher in the immediate versus delayed PCI group (P = 0.02), although there was no difference between groups in peak CK-MB, peak troponin, or peak CK-MB ratio. Our data suggest that in STEMI patients with patent IRA, optimal ST-segment resolution, and thrombus-containing lesion, deferred PCI when patients are given dual antiplatelet therapy, antithrombin agents, and GPIIb-IIIa inhibitors results in a higher procedural success rate, without an increased risk of MACE.

Abstract 4708: Rapid Resolution of ST Segment Elevation and Recovery of Function in Acute Myocardial Infarction Treated with Low Dose Intravenous Thrombolytics, Transthoracic Ultrasound, and Intravenous Microbubbles

Rapid non-invasive methods of recanalizing acutely thrombosed coronary arteries and restoring microcirculatory flow are needed. Failure of ST segment elevation to resolve on the 12 lead electrocardiogram is a marker of microvascular no reflow, and occurs in over 30% of acute myocardial infarctions treated with primary percutaneous interventions. Transthoracic ultrasound (TTU) and intravenous (IV) microbubbles (MB) have the potential to increase epicardial recanalization (RC) when used with low dose thrombolytic therapy (TT). We hypothesized that this therapy may also dissolve microvascular thrombi, and thus improve microvascular recovery during treatment of an acute coronary thrombosis. In 45 closed chest pigs, acute left anterior descending (LAD) thromotic occlusions were created, followed by randomized treatment to either a) IV low dose TT alone (50,000 u/kg recombinant urokinase; n=15), or b) IV low dose TT combined with IV lipid encapsulated MB (ImaRx Therapeutics, Inc) and TTU (1.5 MHz diagnostic transducer using 1.9 MI therapeutic impulses applied only when low MI imaging detected MB within the affected risk area; n=30). Resolution of ST segment elevation as well as wall thickening (WT) within the central portion of the risk area were analyzed in pigs that had epicardial RC versus those that did not exhibit RC in the IV MB treated groups. Epicardial RC occurred within 60 minutes in 15 pigs (50%) treated with IV MB and TTU (p&lt; 0.01 compared to IV TT alone;Table ). Significant &gt;50% ST segment resolution occurred in over 90% of pigs with epicardial RC treated with TT and MB, but also in six of 15 pigs that did not have RC. In these six pigs, WT within the risk area increased similar to the pigs which had epicardial RC (Table ). Diagnostic TTU and IV microbubbles improve microvascular perfusion even if epicardial RC is not achieved, leading to rapid recovery of function. Both epicardial and microvascular reflow can be achieved with this technique. ST segment and WT Changes Before and Following Treatment

ST-Segment Recovery and Outcome After Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Primary percutaneous coronary angioplasty is an effective and widely adopted treatment for acute myocardial infarction. A simple method of determining prognosis after primary percutaneous coronary intervention (PCI) would facilitate appropriate care and expedite hospital discharge. Thus, we determined the prognostic importance of various measures of ST-segment-elevation recovery after primary PCI in a large, contemporary cohort of patients with ST-elevation myocardial infarction. We analyzed ECG data describing the magnitude and extent of ST-segment elevation and deviation before and early after (ie, 30 minutes) primary PCI in the study cohort of 4866 subjects with electrocardiographically high-risk ST-elevation myocardial infarction enrolled in the Assessment of PEXelizumab in Acute Myocardial Infarction (APEX-AMI) trial. Associations among 6 methods for calculating ST-segment recovery, biomarker estimates of infarct size (ie, peak creatine kinase, creatine kinase-MB, and troponin I and T), and prespecified clinical outcomes (ie, rates of 90-day death and 90-day death, heart failure, or shock) were examined. All ST-segment-recovery methods provided strong prognostic information regarding clinical outcomes. A simple ST-segment-recovery method of residual ST-segment elevation measurement in the most affected lead on the post-PCI ECG performed as well as complex methods that required comparison of pre- and post-PCI ECGs or calculation of summed ST-segment deviation in multiple leads (ie, worst-lead residual ST elevation: adjusted hazard ratio for 90-day death rate [reference <1 mm]: 1 to <2 mm, 1.23 [95% CI 0.74 to 2.03]; > or =2 mm, 2.22 [95% CI 1.35 to 3.65], corrected c-index=0.832; 90-day death/congestive heart failure/shock [reference <1 mm]: 1 to <2 mm, 1.55 [95% CI 1.06 to 2.26]; > or =2 mm, 2.33 [95% CI 1.59 to 3.41], corrected c-index=0.802). Biomarker estimates of infarct size declined in association with enhanced ST-segment recovery. An ECG performed early after primary PCI is a simple, widely available, inexpensive, and powerful prognostic tool applicable to patients with ST-elevation myocardial infarction.

Relationship Between Collateral Circulation and Successful Myocardial Reperfusion in Acute Myocardial Infarction: A Subanalysis of the PREMIAR Trial

The aim of this study was to determine whether the presence of collateral circulation had a beneficial effect following primary angioplasty. In all, 114 patients who underwent primary angioplasty were included. Patients with collateral circulation had lower basal ST-segment deviation (P = .004), white cell count ( P = .001), peak creatine kinase (P = .001), and regional wall motion score values (P = .03) than patients without collateral circulation. After the procedure, the group with collaterals was associated with higher rates of normal myocardial blush, complete ST resolution, and shorter time to stable ST-recovery. Multivariable logistic analysis identified the presence of collateral circulation as independent predictor of normal myocardial blush (adjusted odds ratio = 3.98, 95% confidence interval, 1.12-14.09; P = .033) and rapid reperfusion (time to stable ST-segment recovery <7 minutes, adjusted odds ratio = 4.0, 95% confidence interval, 1.57-10.20; P = .004). The presence of collateral circulation has a protective effect on infarct size, resulting in faster reperfusion.

Reperfusion ventricular arrhythmia 'bursts' in TIMI 3 flow restoration with primary angioplasty for anterior ST-elevation myocardial infarction: a more precise definition of reperfusion arrhythmias

We sought to define reperfusion-induced ventricular arrhythmias (VAs) more precisely through simultaneous angiography, continuous ST-segment recovery, and beat-to-beat Holter analyses in subjects with anterior ST-elevation myocardial infarction (STEMI) undergoing primary angioplasty [percutaneous coronary intervention (PCI)]. All 157 subjects with final TIMI 3 flow had continuous 12-lead electrocardiography with simultaneous Holter recording initiated prior to PCI for continuous ST-segment recovery and quantitative VA analyses. Ventricular arrhythmia bursts were detected against subject-specific background VA rates using a statistical outlier method. For temporal correlations, timing and quality of reperfusion were defined as first angiographic TIMI 3 flow with >or=50% stable ST-segment recovery. Almost all subjects had VAs [156/157 (99%)], whereas VA bursts during or subsequent to reperfusion occurred in 97/157 (62%). The majority of VA bursts (72%) arose within 20 min of reperfusion (95% CI: 26.7, 72), with onset at a median of 4 min post-reperfusion (IQR: 0-43) Bursts comprised a median of 1290 ventricular premature complexes (VPCs) (IQR: 415-4632) and persisted for a median of 105 min (IQR: 35-250). Most background VAs occurred as single VPCs; bursts typically comprised runs of three or more VPCs. Subjects with bursts had higher absolute peak ST segments and more frequent worsening of ST elevation immediately after reperfusion. Ventricular arrhythmia bursts temporally associated with TIMI 3 flow restoration and stable ST-segment recovery (reperfusion VA bursts) can be precisely defined in subjects with anterior STEMI and may constitute a unique electric biosignal of myocellular response to reperfusion.

Relationship between Microvascular Resistance and Perfusion in Patients with Reperfused Acute Myocardial Infarction

Despite its prognostic importance, accurate assessment of microvascular perfusion in patients with ST elevation acute myocardial infarction (STEMI) is difficult. As a new tool, the index of microvascular resistance (IMR) measurement provides us a new opportunity for interrogating microvascular condition after STEMI. In this study, we measured IMR in infarct-related artery (IRA) and explored its relation with other indices which have been suggested to evaluate microvascular perfusion in patients with reperfused STEMI. Forty-two patients with STEMI treated successfully with primary percutaneous coronary intervention (pPCI) were prospectively included. After 48 hours following pPCI, patients were recatheterized and IMR, coronary flow reserve (CFR), systolic and mean coronary wedge pressures (CWPs and CWPm) pressure-derived collateral flow index (CFIp) were measured in IRA by using intracoronary pressure-temperature sensor tipped guide wire. Myocardial blush grade was assessed from the second angiogram. Coronary flow velocity pattern (diastolic deceleration time: DDT) was examined with transthoracic echocardiography 48 hours after pPCI. Percentage of ST-segment recovery was calculated from surface ECG (STR%). IMR well correlated with CWPs (r = 0.70, P < 0.001), CWPm (r = 0.59, P < 0.001), CFIp (r = 0.65, P < 0.001), CFR (r =-0.50, P = 0.001), and DDT (r =-0.59, P = 0.001). Correlations of IMR to non/semiinvasive indices like myocardial blush grades (MBG) (r =-0.42, P = 0.007) and STR (r =-0.37, P = 0.024) are somewhat weaker. Given its simplicity of measurement, independence from the presence of an epicardial stenosis, and good correlation with all measures of microvascular obstruction used in this study, IMR may prove to be a valuable modality for evaluating the microcirculation.

Impact of collateral flow on myocardial reperfusion and infarct size in patients undergoing primary angioplasty for acute myocardial infarction

The prognostic impact of baseline collateral flow of the infarct-related artery (IRA) in patients undergoing primary percutaneous coronary intervention (PCI) remains controversial. We sought to examine the impact of baseline collateral flow to the IRA on reperfusion success, infarct size, and clinical outcomes in patients undergoing primary PCI for acute myocardial infarction (AMI). Acute procedural, 30-day, and 6-month clinical outcomes were assessed after primary PCI among patients enrolled in the EMERALD trial (n = 501 with AMI within 6 hours of onset). Patients with collateral flow to the IRA (Rentrop grade 2 or 3) more commonly had prior stable angina, less commonly had failed thrombolysis and left anterior descending artery occlusion, and presented with less ST-segment elevation. Myocardial reperfusion assessed by ST-segment recovery and myocardial blush was similar in patients with and without baseline collateral flow to the IRA. Infarct size (assessed by technetium Tc 99m sestamibi) was similar among patients with and without baseline collateral flow in anterior infarction (mean 28.5% vs 31.2%, respectively; P = .59) and nonanterior infarction (12.5% vs 12.1%, respectively; P = .81). There were no differences in the rates of major adverse cardiac events at 30 days or 6 months according to baseline IRA collateral flow. Among patients undergoing primary PCI for AMI within 6 hours of symptom onset, we found no significant relationship between baseline collateral flow and either reperfusion success, infarct size, or subsequent clinical outcomes.

Impact of multivessel disease on reperfusion success and clinical outcomes in patients undergoing primary percutaneous coronary intervention for acute myocardial infarction

We sought to investigate the impact of multivessel coronary artery disease (CAD) on reperfusion success and prognosis following primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). The influence of multivessel disease on myocardial reperfusion and subsequent survival after primary PCI has not been studied. In the CADILLAC trial, primary PCI was performed in 2082 patients of any age with AMI within 12 h of symptom onset. Myocardial perfusion post-PCI assessed by ST-segment recovery and myocardial blush and clinical outcomes were stratified by the extent of CAD. Single-, double-, and triple-vessel disease were present in 1066 (51.2%), 692 (33.2%), and 324 (15.6%) patients, respectively. Patients with multivessel disease compared with those with single-vessel disease undergoing primary PCI were significantly more likely to have absent ST-segment recovery (13.3 vs. 7.4%, P = 0.01), though the rates of post-procedural TIMI-3 flow (89.7 vs. 88.9%, P = 0.66) and grade 2 or 3 myocardial blush (51.2 vs. 51.5%, P = 0.91) in the infarct vessel were comparable. By 1 year, the cumulative incidence of death for patients with single-, double-, and triple-vessel disease was 3.2, 4.4, and 7.8%, respectively (P = 0.003), and the composite rate of major adverse cardiac events (MACE) was 14.8, 19.5, and 23.6%, respectively (P = 0.0006). By multivariable analysis, the presence of triple-vessel disease was the strongest predictor of 1-year death [hazard ratio (HR) = 2.60, P = 0.009], death and re-infarction (HR = 1.88, P = 0.03), and MACE (HR = 1.80, P = 0.0009). Patients with extensive CAD in vessels remote from the infarct-related artery have reduced reperfusion success and an adverse prognosis following primary PCI in AMI. Future studies regarding the optimal treatment of patients with multivessel disease and AMI are warranted.