Early identification of impaired myocardial reperfusion with serial assessment of ST segments after percutaneous transluminal coronary angioplasty during acute myocardial infarction

Stenting versus non-stenting treatment of intermediate stenosis culprit lesion in acute ST-segment elevation myocardial infarction: a multicenter randomized clinical trial

Background

The benefit/risk ratio of stenting in acute ST-segment elevation myocardial infarction (STEMI) patients with single vessel intermediate stenosis culprit lesions merits further study, therefore the subject of the present study.

Methods and results

It was a prospective, multicenter, randomized controlled trial. Between April 2012 and July 2015, 399 acute STEMI patients with single vessel disease and intermediate (40%–70%) stenosis of the culprit lesion before or after aspiration thrombectomy and/or intracoronary tirofiban (15 µg/kg) were enrolled and were randomly assigned (1: 1) to stenting group (n = 201) and non-stenting group (n = 198). In stenting group, patients received pharmacologic therapy plus standard percutaneous coronary intervention (PCI) with stent implantation. In non-stenting group, patients received pharmacologic therapy and PCI (thrombectomy), but without dilatation or stenting. Primary endpoint was 12-month rate of major adverse cardiac and cerebrovascular events (MACCE), a composite of cardiac death, non-fatal myocardial infarction (MI), repeat revascularization and stroke. Secondary endpoints were 12-month rates of all cause death, ischemia driven admission and bleeding complication. Median follow-up time was 12.4 ± 3.1 months. At 12 months, MACCE occurred in 8.0% of the patients in stenting group, as compared with 15.2% in the non-stenting group (adjusted HR: 0.42, 95% CI: 0.19–0.89, P = 0.02). The stenting group had lower non-fatal MI rate than non-stenting group, (1.5% vs. 5.5%, P = 0.03). The two groups shared similar cardiac death, repeat revascularization, stroke, all cause death, ischemia driven readmission and bleeding rates at 12 months.

Conclusions

Stent implantation had better efficacy and safety in reducing MACCE risks among acute STEMI patients with single vessel intermediate stenosis culprit lesions.

Early versus late ST-segment resolution and clinical outcomes after percutaneous coronary intervention for acute myocardial infarction

Background. Absence of complete ST-segment resolution (STR) after percutaneous coronary intervention (PCI) for ST-segment-elevation myocardial infarction (STEMI) is a determinant of mortality. Traditionally, STR is determined on the coronary care unit (CCU) 60 to 90 minutes after the initiation of reperfusion therapy. We studied the prognostic value of STR immediately after PCI. Methods. We analysed 223 consecutive patients with STEMI and successful PCI. Continuous ECG data were collected during PCI and at 30 minutes after arrival on the CCU (mean time 81±17 minutes after reflow of the culprit artery). Patients were divided into three groups: patients with complete STR immediately after PCI ('early'), patients with complete and persistent STR at 30 minutes on the CCU, but not immediately after PCI ('late') and patients without STR. One-year follow-up was obtained for death and rehospitalisation for major adverse cardiac events. Cox proportional hazards regression was used to evaluate the association between STR and outcome. Results. Early STR occurred in 115 (52%) and late STR in 43 (19%) patients. Patients with early or late STR had a lower incidence of one-year cardiac death than those without STR (1.9 vs. 9.2%; p=0.02). In contrast, rehospitalisation occurred more frequently in patients with early or late STR (20.3 vs. 6.2%; p=0.009). As compared with patients without STR, early and late STR had a similar prognostic value (hazard ratios [95% confidence interval] for cardiac death 0.40 [0.08-2.03] and 0.25 [0.03-2.08]).Conclusions. We found no (major) change in prognostic value of STR during the 0 to 90 minutes time window after PCI. (Neth Heart J 2010;18:416-22.).

Preservation of myocardial viability within the risk area by intravenous nicorandil before primary coronary intervention in patients with acute myocardial infarction

OBJECTIVE

To investigate the cardioprotective effect of intravenous nicorandil before primary percutaneous coronary intervention (PCI) on preservation of myocardial viability, we studied 199 consecutive patients with acute myocardial infarction.

METHODS

Nicorandil was given intravenously on admission (before primary PCI). Echocardiography and technetium-99m tetrofosmin perfusion imaging were performed before and 1 month after primary PCI. Echocardiographic asynergic score before primary PCI was used to define the size of risk area, whereas the sum of scintigraphic defect grade before primary PCI was used to estimate myocardial viability within the area at risk. The change (before primary PCI and 1 month after primary PCI) in asynergic score and scintigraphic salvage index were calculated.

RESULTS

Patients were divided into nicorandil (n=101) and control (n=98) groups. Although asynergic score before primary PCI was not different between the two groups (nicorandil=3.5+/-2.1 and control=3.9+/-1.5), myocardial viability was preserved in nicorandil group (defect score=11.0+/-4.0) than that in control group (defect score=14.0+/-4.7, P<0.0001). Multivariate analysis revealed that the presence of antegrade flow (P=0.015) and nicorandil (P<0.0001) were independently associated with preserved myocardial viability before primary PCI. Moreover, the greater reduction in asynergic score (66+/-41 vs. 49+/-23%, P=0.0006) and larger salvage index (65+/-25 vs. 53+/-26%, P=0.0015) were observed in nicorandil group compared with the control group.

CONCLUSION

Intravenous administration of nicorandil before primary PCI preserved myocardial viability within the risk area, which leads to greater myocardial salvage and better functional recovery after primary PCI.

Acute heart failure in patients with acute myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND

Scanty data exist about the relation between acute heart failure (HF) and acute myocardial infarction (AMI).

AIM

To assess the impact of HF on outcome in AMI patients treated with primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Out of 2,089 AMI patients, 82% did not present HF, 17% presented HF on admission and 1% developed HF after hospitalisation. Predictors of HF on admission were age, diabetes, prior MI, time delay to admission, anterior location, and TIMI grade 0-1 in the culprit vessel. Predictors of HF during hospitalisation were age and peak creatine kinase. The 1- and 6-month mortalities were 1.1% and 2.2%, 8% and 12%, 26% and 33% in patients without HF, with HF on admission and after hospitalisation, respectively. The risk of death was higher in patients with HF than in patients without HF (HR 3.47), as well as in patients with HF after admission (HR 5.19) than in patients with HF on admission (HR 2.44).

CONCLUSIONS

In a primary PCI setting, the incidence of HF on hospital admission remains high, but mortality is lower when compared with historical patient series. Primary PCI may prevent the development of HF during hospitalisation; however, when HF develops, the prognosis remains severe.

Relation of corrected thrombolysis in myocardial infarction frame count and ST-segment resolution to myocardial tissue perfusion after acute myocardial infarction

OBJECTIVES

To evaluate myocardial tissue perfusion by corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and ST-segment resolution after successful percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI).

BACKGROUND

Early and sustained potency of infarct-related artery (IRA) has become the main goal of reperfusion therapy in patients with AMI. However, myocardial tissue perfusion may remain impaired even after the achievement of TIMI grade 3 flow of the epicardial artery without residual stenosis.

METHODS

CTFC was measured after successful PCI in 63 patients with first AMI. The extent of ST-segment resolution was recorded 1 hr after reperfusion therapy. The wall motion score index (WMSI) was assessed before and 1 month after PCI. Then we studied the correlation between CTFC, ST-segment resolution, and WMSI.

RESULTS

According to CTFC, the patients with TIMI grade 3 flow after PCI were divided into two groups: CTFC fast group and CTFC slow group. CTFC fast group had higher percentage of complete ST resolution (54.1% vs. 25.0%, P < 0.05) and lower percentage of no ST resolution (2.6% vs. 29.2%, P < 0.05). Improvement of WMSI in the CTFC fast group was significantly greater than that of the CTFC slow group (1.30 +/- 0.41 vs. 0.64 +/- 0.30, P < 0.05). CTFC had a significant negative correlation with the change in WMSI (r = -0.75, P < 0.01).

CONCLUSIONS

Combined with ST-segment resolution, CTFC could predict risk for patients with successful reperfusion therapy after AMI and provide evidence for additional adjunctive treatment.

Significance of additional ST segment elevation in patients with no reflow after angioplasty for acute myocardial infarction

OBJECTIVES

We sought to evaluate the incidence, timing, and clinical significance of additional increase in ST segment elevation (ST-SE) in patients showing no reflow after angioplasty for acute myocardial infarction.

METHODS

We studied 26 patients with acute myocardial infarction showing myocardial contrast echocardiography no reflow after successful angioplasty. Baseline and 6-month 2-dimensional echocardiograms were obtained in 21 surviving patients.

RESULTS

After angioplasty, 13 patients showed greater than 30% additional increase in ST-SE (group 1), whereas 13 did not (group 2). Baseline clinical, echographic, and angiographic characteristics, and 6-month patency and restenosis rate, were similar between the two groups. From baseline to 6 months, a similar global and regional systolic function was found between the two groups, whereas a higher increase in left ventricular end-diastolic volume occurred in group 1 (135 +/- 45 vs 168 +/- 42 mL, P = .033). The additional increase in ST-SE was not associated with more severe microvascular damage (myocardial contrast echocardiography score index: 0.14 +/- 0.26 vs 0.22 +/- 0.27), higher peak creatine kinase value (4888 +/- 2533 vs 3109 +/- 2055 U/L, P = .061), higher incidence of left ventricular remodeling (73% vs 60%, P = .537), or worse outcome (26 +/- 24 months) such as death (15% vs 23%, P = .619), hospitalization for heart failure (8% vs 23%, P = .277), or reinfarction (8% vs 0%, P = .308).

CONCLUSIONS

Our data show that in patients showing no reflow after angioplasty a transient additional increase in ST-SE occurs in half of patients. The prognostic value of additional increase in ST-SE remains uncertain in the era of primary angioplasty.

The effect of verapamil on the restoration of myocardial perfusion and functional recovery in patients with angiographic no-reflow after primary percutaneous coronary intervention

OBJECTIVE

Angiographic thrombolysis in myocardial infarction (TIMI) flow grade < or = 2 after primary percutaneous coronary intervention (PCI), defined as angiographic no-reflow, predicts poor functional recovery in patients with acute myocardial infarction. We investigated the effect of verapamil on the restoration of myocardial perfusion and functional recovery in patients with angiographic no-reflow after PCI.

METHODS

99mTc tetrofosmin single photon emission computed tomographic (SPECT) imaging was performed (before, immediately after and 1 month after PCI) in 101 consecutive patients with acute myocardial infarction. The defect score was calculated as the sum of perfusion defect in a 13-segment model (scores of 3, complete defect to 0, normal perfusion). The asynergic score, defined as the number of asynergic segments, was assessed by echocardiography before and 1 month later. Multiple logistic regression analysis was performed to elucidate the effect of verapamil administration.

RESULTS

Of 101 patients, 32 (31%) had angiographic no-reflow and were divided into two groups: 18 patients with verapamil (group 1) and 14 patients without verapamil (group 2). Sixty-nine patients had TIMI grade 3 reflow after PCI (group 3). The change in the defect score 1 month after PCI in group 1 was significantly larger than that in group 2 (P = 0.003). The asynergic score improved more at 1 month in group 1 compared to that in group 2 (P = 0.007). Moreover, logistic regression analysis revealed that TIMI grade reflow < or = 2 after PCI (P = 0.04, OR = 5.51), the defect score before PCI (P = 0.03, OR = 1.15), the asynergic score before PCI (P = 0.01, OR = 0.64) and the administration of verapamil (P = 0.002, OR = 22.4) were independently associated with successful myocardial reperfusion immediately after PCI.

CONCLUSIONS

Intracoronary verapamil restored myocardial perfusion in patients with angiographic no-reflow after PCI and lead to better functional recovery after acute myocardial infarction.

Potential significance of spontaneous and interventional ST-changes in patients transferred for primary percutaneous coronary intervention: observations from the ST-MONitoring in Acute Myocardial Infarction study (The MONAMI study)

AIMS

In patients with ST-elevation myocardial infarction (STEMI) scheduled for primary percutaneous coronary intervention (primary PCI), acute risk-assessment may be valuable for tailoring of adjunctive therapy at the time of coronary intervention. The present study was designed to quantify pre-, per-, and post-interventional ST-changes, to evaluate whether a pre-specified continuous ST-monitoring classification provides potential prognostic information in the pre- and per-interventional phase, and to compare post-interventional ST-resolution parameters derived from continuous ST-monitoring and snapshot ECGs, respectively.

METHODS AND RESULTS

In 92 STEMI patients, continuous ST-monitoring was initiated in the pre-hospital phase and continued during and 90 min following PCI. Patients were divided into three groups: (A) patients achieving spontaneous ST-resolution before PCI; (B) patients with preserved ST-elevation immediately before PCI and with no increase in ST-elevation during PCI; and (C) patients with preserved ST-elevation immediately before PCI and with increase in ST-elevation during PCI. Groups A (n=22), B (n=43), and C (n=27) differed in peak level of troponin-T (1.4, 4.7, and 7.2 microg/L, P<0.001), creatinine kinase MB isoenzyme (35, 150, and 325 microg/L, P<0.001), and N-terminal pro-brain natriuretic peptide (Nt-pro-BNP) (183, 175, and 269 pmol/L, P=0.084) during admission, and left ventricular ejection fraction evaluated within 2 h of PCI (0.53, 0.48, and 0.45, P=0.047) and after 3 months (0.58, 0.54, and 0.45, P<0.001). Groups B and C also differed in time from first balloon inflation to > or =70% resolution of ST-elevation (14 vs. 42 min, P=0.002), whereas no differences were observed in traditional 90 min ST-resolution analysis or angiographically assessed parameters.

CONCLUSION

STEMI patients transferred for primary PCI are heterogeneous with respect to pre- and per-interventional ST-changes, and a pre-specified ST-monitoring classification seems useful for stratification of patients at time of PCI into groups with low, intermediate, and high risk profile. Furthermore, post-interventional ST-monitoring indicates that traditional 90 min ST-resolution analysis may have limited value in the era of primary PCI.

Prehospital evaluation in ST-elevation myocardial infarction patients treated with primary percutaneous coronary intervention

In patients with ST-elevation myocardial infarction, fast initiation of reperfusion therapy is mandatory. It is well established that prehospital diagnosis results in earlier initiation of fibrinolysis, but there is limited evidence concerning the value of prehospital evaluation in patients treated with primary percutaneous coronary intervention (PCI). The present paper proposes various prehospital strategies that may be of relevance in treating the latter patients: (1) a substantial reduction in treatment delay may be achieved by prehospital diagnosis, especially if combined with rerouting of patients directly to interventional hospital; (2) use of telemedicine may allow a widespread implementation of a prehospital diagnostic program; (3) a rerouting strategy may result in prolonged transportation. In this setting, continuous real-time 1-lead ECG transmission from ambulance to hospital may allow physicians to support ambulance personnel in the treatment of arrhythmias during transportation; and (4) equipment used for prehospital ECG acquisition and transmission has built-in features for continuous ST-segment monitoring. It is hypothesized that continuous ST-segment monitoring performed in the prehospital phase and during primary PCI may provide important prognostic information, with the potential of triaging future pharmacological and interventional treatment at time of PCI.

Prognostic implication of ST-segment resolution following primary percutaneous transluminal coronary angioplasty for ST-elevation acute myocardial infarction

BACKGROUND

ST-segment changes have been shown to correlate with myocardial tissue perfusion. Complete ST-segment resolution after thrombolysis in acute myocardial infarction is associated with lower mortality and better left ventricular function. Primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction restores better epicardial coronary flow to the infarct-related artery than thrombolysis. However, ST changes may persist and flow can remain poor despite a patent vessel.

AIM

To examine the prognostic implication of ST-segment resolution immediately following primary and rescue PTCA for ST-elevation acute myocardial infarction (STEMI).

METHODS

Records of 201 consecutive primary and rescue PTCA performed at Westmead Hospital for STEMI from January 2000 to December 2001 were reviewed. ST-segment elevation (taken 20 ms after the end of the QRS complex) was measured immediately before and after the procedure. ST-segment resolution of greater than 70% after the procedure was considered as -'complete' ST-segment resolution, whereas ST-segment resolution of less than 70% was considered as 'incomplete' ST-segment resolution.

RESULTS

Of the 201 patients, 117 (58%) had complete ST-elevation resolution and 84 (42%) did not. There was a significant difference in survival free of major adverse cardiovascular events; 60% of those with complete ST-segment resolution were event-free at 2 years compared with 35% of those patients without complete ST-segment resolution.

CONCLUSION

ST-segment resolution after primary and rescue PTCA for STEMI is associated with significantly higher event-free survival. The goal of primary angio-plasty should be the restoration of normal epicardial flow with normalization of ST-segments.

Prognostic utility of comparative methods for assessment of ST-segment resolution after primary angioplasty for acute myocardial infarction: the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial

OBJECTIVE

This study was done to assess and compare the prognostic significance of multiple methods for measuring ST-segment elevation resolution (STR) following primary percutaneous coronary intervention (PCI).

BACKGROUND

Resolution of ST-segment elevation (STE) is a powerful predictor of both infarct-related artery patency and mortality in acute myocardial infarction (AMI). Recent thrombolytic studies have suggested that simple measures of STR may be as powerful as more complex algorithms. The optimal method of assessing STR following primary PCI has not been studied.

METHODS

We analyzed 700 patients with technically adequate baseline and post-PCI electrocardiograms from the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial. Five methods were used to assess STR: 1) summed %STR across multiple leads (SigmaSTR); 2) %STR in the single lead with maximum baseline STE (MaxSTR); 3) absolute maximum STE before the procedure; 4) absolute maximum STE after intervention (MaxSTPost); and 5) a categorical variable based upon MaxSTPost (High Risk).

RESULTS

At 30 days, SigmaSTR, MaxSTR, and MaxSTPost all correlated strongly with mortality (p = 0.004, p = 0.005, and p < 0.0001, respectively) and the combined end point of mortality or reinfarction (p = 0.001, p = 0.001, and p < 0.0001). At one year, SigmaSTR and MaxSTPost correlated with mortality (p = 0.04, p = 0.0001), reinfarction (p = 0.02, p = 0.0015), and the combined end point (p = 0.02, p < 0.0001). By multivariate analysis, only the simpler measures of MaxSTPost and High Risk categorization independently predicted all outcomes at both time points.

CONCLUSIONS

The STR following primary PCI in AMI correlates strongly with mortality and reinfarction, independent of target vessel patency. The simple measure of the maximal residual degree of STE after primary PCI is a strong independent predictor of both survival and freedom from reinfarction at 30 days and 1 year.

Continuous ST-Segment Monitoring

Continuous ST-segment monitoring has been shown to be beneficial for patients with acute coronary syndromes as well as for other patients in the intensive care unit (ICU). This article reviews the significance and value of continuous ST-segment monitoring with emphasis on the value of 12-lead ST-segment monitoring across the continuum of care from the emergency department, to the cardiac catheterization laboratory, the ICU, and the telemetry unit.

Quantitative estimation of myocardial salvage after primary percutaneous transluminal coronary angioplasty in patients with angiographic no reflow

Angiographic Thrombolysis in Myocardial Infarction (TIMI) flow grade <or=2 after primary percutaneous transluminal coronary angioplasty (PTCA), defined as angiographic no reflow, predicts poor left ventricular functional recovery and survival in patients with acute myocardial infarction (MI). To determine the relation between angiographic coronary flow and myocardial salvage in the acute phase of MI, serial technetium-99m tetrofosmin imaging was performed before, immediately after and 1 month after PTCA in 117 patients. Angiographic no reflow was observed in 23 patients (20%; group 1), while 94 patients did not have angiographic no reflow (group 2). Although there was no significant difference in the defect score before PTCA between the two groups (group 1, 14.4+/-5.7; group 2, 13.5+/-4.6), the defect score immediately after PTCA in group 1 was significantly higher than that in group 2 (group 1, 12.8+/-5.1; group 2, 8.9+/-4.6; P<0.0001). A significantly smaller change in the defect score after PTCA (before minus immediately after PTCA) was observed in group 1 as compared with group 2 (group 1, 1.7+/-2.0; group 2, 4.5+/-2.9; P<0.0001). Twenty patients in group 1 (87%) had impaired myocardial reperfusion (<4 change in the defect score immediately after PTCA), as compared with 36 patients (38%) in group 2; this difference was significant (chi(2)=17.5, P<0.0001). The sensitivity, specificity and accuracy of angiographic no reflow in estimating impaired myocardial reperfusion were 36%, 95% and 67%, respectively. Thus, angiographic no reflow is a highly specific, although not sensitive, marker of impaired myocardial reperfusion immediately after primary PTCA.

Use of radionuclide imaging in acute coronary syndromes

The triage of patients presenting to the emergency department (ED) with acute chest pain is a diagnostic challenge. Radionuclide myocardial perfusion imaging has been shown to have favorable diagnostic and prognostic value in this setting, with an excellent early sensitivity to detect acute myocardial infarction (MI) not achieved by other testing modalities. A normal resting perfusion imaging study has been shown to have a negative predictive value of over 99% to exclude MI. Observational and randomized trials of both rest and stress imaging in the ED evaluation of patients with chest pain have demonstrated reductions in unnecessary hospitalizations and cost savings compared with routine care. Perfusion imaging has also been used in risk stratification after MI, and for measurement of infarct size to evaluate reperfusion therapies. Novel "hot spot" imaging radiopharmaceuticals that visualize infarction or ischemia are currently undergoing evaluation and hold promise for future imaging of acute coronary syndromes.

[Prognostic value of persistent ST-segment elevation after successful primary angioplasty]

INTRODUCTION AND OBJECTIVES

A variable percentage of patients with myocardial infarction treated with successful primary angioplasty and restoration of coronary flow show persistent ST-segment elevation, probably due to inadequate cellular reperfusion. We studied if persistent ST-segment elevation was a predictor of worse prognosis.

PATIENTS AND METHODS

We comparatively studied the clinical and angiographic results of 116 acute myocardial infarction patients after successful primary angioplasty, which were classified into two groups depending on the persistence (> 50%) or reduction (</= 50%) of ST-segment elevation between the electrocardiograms recorded before and after coronary angioplasty.

RESULTS

In 96 patients (Group I) the ST-segment elevation improved after angioplasty and in 20 patients (Group II) there was no improvement. Baseline characteristics were similar in both groups except for Killip class 4, which was more prevalent in group II (7.2 vs. 25%; p = 0.01). There were no differences in the characteristics or results of the procedure. There was more myocardial damage in group II (CK 3,149 1,636 vs. 2,185 2,010 U/l; p = 0.02), associated with a more impaired left ventricular ejection fraction in the late angiographic control (47 16 vs 55 16%; p = 0.05). At a one-year follow-up the mortality was 8.3% in group I and 30% in group II (p = 0.01).

CONCLUSIONS

The persistence of ST-segment elevation after successful primary angioplasty identifies a group of patients that may suffer an increased risk of adverse events in spite of good epicardial flow.