Association of noninvasive markers of coronary artery reperfusion to assess microvascular obstruction in patients with acute myocardial infarction treated with primary angioplasty

Predictors and prognosis of early ischemic mitral regurgitation in the era of primary percutaneous coronary revascularisation

Background

Studies assessing ischemic mitral regurgitation (IMR) comprised of heterogeneous population and evaluated IMR in the subacute setting. The incidence of early IMR in the setting of primary PCI, its progression and clinical impact over time is still undetermined. We sought to determine the predictors and prognosis of early IMR after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI).

Methods

Using our primary PCI database, we screened for patients who underwent ≥2 transthoracic echocardiograms early (1–3 days) and late (1 year) following primary PCI. The primary outcomes were: (1) major adverse events (MACE) including death, ischemic events, repeat hospitalization, re-vascularization and mitral repair or replacement (2) changes in quantitative echocardiographic assessments.

Results

From January 2006 to July 2012, we included 174 patients. Post-primary PCI IMR was absent in 95 patients (55%), mild in 60 (34%), and moderate to severe in 19 (11%). Early after primary PCI, IMR was independently predicted by an ischemic time > 540 min (OR: 2.92 [95% CI, 1.28 – 7.05]; p = 0.01), and female gender (OR: 3.06 [95% CI, 1.42 – 6.89]; p = 0.004). At a median follow-up of 366 days [34–582 days], IMR was documented in 44% of the entire cohort, with moderate to severe IMR accounting for 15%. During follow-up, MR regression (change ≥ 1 grade) was seen in 18% of patients. Moderate to severe IMR remained an independent predictor of MACE (HR: 2.58 [95% CI, 1.08 – 5.53]; p = 0.04).

Conclusions

After primary PCI, IMR is a frequent finding. Regression of early IMR during long-term follow-up is uncommon. Since moderate to severe IMR post-primary PCI appears to be correlated with worse outcomes, close follow-up is required.

Predictive value of ischemic mitral regurgitation during the acute phase of ST elevation myocardial infarction treated with primary coronary intervention for left ventricular remodeling in long-term follow-up

Reperfusion therapy, mainly primary percutaneous coronary intervention (PCI), has improved survival and lowered complication rate in patients with ST elevation myocardial infarction (STEMI). Nevertheless, some patients develop left ventricular remodeling (LVR) during long-term follow-up.

AIMS

To assess the incidence of ischemic mitral regurgitation (MR) in the acute phase of STEMI treated with primary PCI. To assess prognostic value of MR during acute STEMI for prediction of LVR during long-term follow-up.

METHODS

This is a prospective, single-center study in 83 patients with the first STEMI. Inclusion criteria were as follows: time from symptom onset to PCI less than 12 h and successful restoration of blood flow (thrombolysis in myocardial infarction 3) in the infarct-related coronary artery. Transthoracic echocardiography was performed at discharge and 6 months after the MI.

RESULTS

At hospital discharge, ischemic MR was found in 35 (42%) patients. At 6 months follow-up, LVR was present in 21 (25%) patients. Univariate analysis revealed that remodeling could be predicted by age, weight, treatment with abciximab, left ventricular ejection fraction (LVEF), leaflets coaptation, coaptation height, tenting area, presence of MR, degree of MR. The best multivariate logistic regression model for remodeling prediction at 6 months was combination of ischemic MR degree (odds ratio (OR)=14.5; 95% confidence interval (CI): 3.89-54.0, P<0.00005), abciximab therapy (OR=0.09; 95% CI: 0.01-0.84, P<0.03) and LVEF (OR=0.89; 95% CI: 0.81-0.99, P<0.03).

CONCLUSION

Ischemic MR in STEMI is frequent, even despite effective primary PCI. The regurgitation grade and lower LVEF assessed at hospital discharge and lack of abciximab administration could predict development of LVR at 6 months.

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.

Comparison of different methods of ST segment resolution analysis for prediction of 1-year mortality after primary angioplasty for acute myocardial infarction

BACKGROUND

Resolution of ST segment elevation corresponds with myocardial tissue reperfusion and correlates with clinical outcome after ST elevation myocardial infarction. Simpler method evaluating the extent of maximal deviation persisting in a single ECG lead was an even stronger mortality predictor. Our aim was to evaluate and compare prognostic accuracy of different methods of ST segment elevation resolution analysis after primary percutaneous coronary intervention (PCI) in a real-life setting.

METHODS

Paired 12-lead ECGs were analyzed in 324 consecutive and unselected patients treated routinely with primary PCI in a single high-volume center. ST segment resolution was quantified and categorized into complete, partial, or none, upon the (1) sum of multilead ST elevations (sumSTE) and (2) sum of ST elevations plus reciprocal depressions (sumSTE+D); or into the low-, medium-, and high-risk groups by (3) the single-lead extent of maximal postprocedural ST deviation (maxSTE).

RESULTS

Complete, partial, and nonresolution groups by sumSTE constituted 39%, 40%, and 21% of patients, respective groups by sumSTE+D comprised 40%, 39%, and 21%. The low-, medium-, and high-risk groups constituted 43%, 32%, and 25%. One-year mortality rates for rising risk groups by sumSTE were 4.7%, 10.2%, and 14.5% (P = 0.049), for sumSTE+D 3.8%, 9.6%, and 17.6% (P = 0.004) and for maxSTE 5.1%, 6.7%, and 18.5% (P = 0.001), respectively. After adjustment for multiple covariates only maxSTE (high vs low-risk, odds ratio [OR] 3.10; 95% confidence interval [CI] 1.11-8.63; P = 0.030) and age (OR 1.07; 95% CI 1.02-1.11; P = 0.002) remained independent predictors of mortality.

CONCLUSIONS

In unselected population risk stratifications based on the postprocedural ST resolution analysis correlate with 1-year mortality after primary PCI. However, only the single-lead ST deviation analysis allows an independent mortality prediction.

Chronic infarct-related artery occlusion is associated with a reduction in capillary density. Effects on infarct healing

AIM

To assess the relationship between infarct-related artery (IRA) stenosis and capillary density and to assess its effect on scar formation in the human heart.

MATERIALS AND METHODS

Morphometric evaluation was performed in 51 human hearts, as follows. Group I non-cardiac death (control), Group II post-Q-wave myocardial infarction (QMI) death and Group III patients who survived QMI and who underwent aneurysmectomy. Using morphometric parameters, the relationship between left ventricle (LV) mass, infarct size, IRA stenosis, cellular hypertrophy and changes in microcirculation were analyzed within the infarcted area and free LV wall.

RESULTS

A significant reduction in capillary density within the infarcted area was noted in group II when compared to the control group (1525.6+/-378.5/mm(2) vs. 2968.7+/-457.3/mm(2); p<0.001). Reduction in capillary density was inversely related to infarct size (r=-0.616; p=0.006) and degree of IRA stenosis (r(S)=-0.512; p=0.03). The most significant reduction in capillary density was observed in patients with total IRA occlusion (1204.6+/-156.9/mm(2) vs. 1676.6+/-245.8/mm(2); p<0.001). Similarly, a reduction in capillary density of over 60% (1030.7+/-241.8/mm(2)) was observed within aneurysms resected surgically.

CONCLUSIONS

The study demonstrated precise quantification of the capillary network in patients following QMI. The most significant reduction in capillary density was observed in patients with chronic total IRA occlusion.

Brief repetitive balloon occlusions enhance reperfusion during percutaneous coronary intervention for acute myocardial infarction: a pilot study

The objective of this study was to determine whether acutely ischemic myocardium may be conditioned during percutaneous coronary intervention for acute myocardial infarction. Ischemic preconditioning is a powerful cardioprotective mechanism that limits infarct size in animal investigations and ischemic sequelae during percutaneous coronary intervention in man. However, the conditioning stimulus in all these studies has been applied prior to the defining episode of ischemia. Seventeen patients undergoing percutaneous coronary intervention for acute myocardial infarction were randomly assigned to a standard ischemic preconditioning protocol (n = 10) or a usual-care control group (n =7). ST segment shift response and Doppler-derived distal coronary velocity data were compared. Despite similar degrees of baseline ST segment elevation, the magnitude of final ST segment elevation in the conditioning group was less than that in controls at the protocol conclusion (conditioning, 1.60 +/- 0.8 mV; control, 4.0 +/- 0.5 mV; P < 0.001). The rate of ST segment resolution was greater in the conditioning group (conditioning, 0.28 +/- 0.1 mV/min; control, 0.12 +/- 0.1 mV/min; P = 0.02). Distal coronary velocimetry indicated significant improvement in coronary flow velocity reserve in the conditioning group at the protocol conclusion (conditioning, 1.8 +/- 0.2; control, 1.4 +/- 0.1; P < 0.008). Brief periods of occlusion and reperfusion during percutaneous intervention for acute myocardial infarction mitigate the extent of ischemic injury and improve distal myocardial perfusion. Such ischemic conditioning represents a potentially useful adjunct to strategies for enhancing reperfusion during acute myocardial infarction.

Impact of intracoronary aspiration thrombectomy during primary angioplasty on left ventricular remodelling in patients with anterior ST elevation myocardial infarction

OBJECTIVE

To evaluate prospectively the impact on left ventricular (LV) remodelling of an intracoronary aspiration thrombectomy device as adjunctive therapy in primary percutaneous coronary intervention (PCI) in patients with anterior ST elevation myocardial infarction (STEMI).

METHODS

76 consecutive patients with anterior STEMI (65.3 (11.2) years, 48 men) were randomly assigned to intracoronary thrombectomy and stent placement (n = 38) or to conventional stenting (n = 38) of the infarct related artery. Each patient underwent transthoracic echocardiography immediately after PCI and at six months. At the time of echocardiographic control, major adverse cardiovascular events (MACE) in terms of death, new onset of myocardial infarction, and hospitalisation for heart failure were also evaluated.

RESULTS

After a successful primary PCI, patients in the thrombectomy group achieved a higher rate of post-procedure myocardial blush grade 3 (36.8% v 13.1%, p = 0.03) and effective ST segment resolution at 90 minutes (81.6% v 55.3%, p = 0.02). Six months after the index intervention, 19 patients (26.8%) developed LV dilatation, defined as an increase in end diastolic volume (EDV) >or= 20%: 15 in the conventional group and four in the thrombectomy group (p = 0.006). Accordingly, at six months patients treated conventionally had significantly higher end systolic volumes (82 (7.7) ml v 75.3 (4.9) ml, p < 0.0001) and EDV (152.5 (18.1) ml v 138.1 (10.7) ml, p < 0.0001) than patients treated with thrombectomy. No differences in cumulative MACE were observed (10.5% in the conventional group v 8.6% in the thrombectomy group, not significant).

CONCLUSION

Compared with conventional stenting, adjunctive aspiration thrombectomy in successful primary PCI seems to be associated with a significantly lower incidence of LV remodelling at six months in patients with anterior STEMI.

ST-segment elevation resolution and outcome in patients treated with primary angioplasty and glucose-insulin-potassium infusion

BACKGROUND

To evaluate the impact of adjunctive high-dose glucose-insulin-potassium (GIK) on ST-segment elevation resolution in patients with ST-segment elevation myocardial infarction (MI).

METHODS

As part of a randomized controlled trial of GIK versus no GIK in patients treated with primary percutaneous coronary intervention (PCI) for ST-elevation MI in a tertiary referral center, we analyzed ST-segment elevation resolution. Paired electrocardiographic recordings (baseline and 3 hours after primary PCI) were available in 612 (65%) of 940 patients.

RESULTS

We analyzed paired electrocardiograms of 310 patients randomized to GIK and 302 control patients. Baseline characteristics of the groups were comparable. Combined complete (>70%) and partial (30%-70%) resolution was more commonly observed in the GIK group (87%) when compared with the control group (78%), odds ratio 1.92 (95% CI 1.23-3.02, P = .004); 1-year mortality was lower in patients with combined complete and partial resolution compared with patients without resolution (3.8% vs 10.3%, P = .011). There was no difference in 1-year mortality between GIK and control patients (5.5% vs 4.3%, P = .58).

CONCLUSIONS

In patients with ST-elevation MI treated with primary PCI, addition of GIK is associated with improved ST-segment elevation resolution. ST-segment elevation resolution is related to improved 1-year survival. No benefit of GIK on 1-year outcome was observed. Future trials should investigate whether GIK-induced improvement of ST-segment elevation resolution results in more favorable clinical outcome.

Off-pump coronary artery bypass surgery: physiology and anaesthetic management †

Increasing interest is being shown in beating heart (off-pump) coronary artery surgery (OPCAB) because, compared with operations performed with cardiopulmonary bypass, OPCAB surgery may be associated with decreased postoperative morbidity and reduced total costs. Its appears to produce better results than conventional surgery in high-risk patient populations, elderly patients, and those with compromised cardiac function or coagulation disorders. Recent improvements in the technique have resulted in the possibility of multiple-vessel grafting in all coronary territories, with a graft patency comparable with conventional surgery. During beating-heart surgery, anaesthetists face two problems: first, the maintenance of haemodynamic stability during heart enucleation necessary for accessing each coronary artery; and second, the management of intraoperative myocardial ischaemia when coronary flow must be interrupted during grafting. The anaesthetic technique is less important than adequate management of these two major constraints. However, experimental and recent clinical data suggest that volatile anaesthetics have a marked cardioprotective effect against ischaemia, and might be specifically indicated. OPCAB surgery requires team work between anaesthetists and surgeons, who must be aware of each other's constraints. Some surgical aspects of the operation are reviewed along with physiological and anaesthetic data.

Current therapy of the right ventricle myocardial infarction

BACKGROUND

Acute myocardial infarction of the right ventricle (AMI-RV) is a separate subgroup within the scope of inferoposterior infarction of the left ventricle. It still represents the population of patients at high risk due to numerous, often hardly predictable complications and high mortality rate.

METHODS

In fifteen-year period (1987-2001) 3,765 patients with the acute myocardial infarction (AMI) of different localizations of both sexes--2,283 males and 1,482 females of the average age 61.4 +/- 4.6 years were treated in our institution. Anterior myocardial infarction was diagnosed in 2,146 (56.9%) patients, inferior in 1,619 (43.1%) patients, out of whom right ventricular infarction (RVI) was confirmed in 384 (23.7%). Thrombolytic therapy was administered in 163 (42.4%) patients with RVI, and in 53 (41.7%) of these patients balloon dilatation was performed with coronary stent implantation in 24 (45.2%).

RESULTS

Favorable clinical effect of the combined thrombolytic therapy and percutaneous transluminal coronary angioplasty (PTCA) was achieved in 51 (96.1%), and in only 2 (3.9%) of patients the expected effect wasn't achieved. Myocardial revascularization was accomplished in 6 (3.6%) and 1 patient died. In 3 (3.4%) patients primary balloon dilatation with the implantation of intracoronary stent was performed within 6 hours from the onset of anginal pain. In the other group of 221 (57.5%) patients with RVI who did not receive thrombolytic therapy, or it had no effect, 26 (11.7%) patients died, which indicated the validity and the efficacy of this treatment (p < 0.01). In the whole group of patients with myocardial infarction of the right ventricle 31 (8.1%) died; in the group that received thrombolytic therapy and PTCA 5 (3.1%) died, while in the group treated in a conservative way 26 (11.7%) died.

CONCLUSION

Combined therapy was successful in the treatment of patients with RVI and should be administered whenever possible, since it was the best prevention of life-threatening complications and the decrease in the mortality of those patients.

[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.