Predictive value of ventricular arrhythmias for patency of the infarct-related coronary artery after thrombolytic therapy

Impact of Late Ventricular Arrhythmias on Cardiac Mortality in Patients with Acute Myocardial Infarction

Objectives

This study investigated the relationship between the timing of ventricular tachycardia or ventricular fibrillation (VT or VF) and prognosis in patients undergoing primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

Background

It is unknown whether the timing of VT/VF occurrence affects the prognosis of patients with AMI.

Methods

From January 2004 to December 2014, 1004 patients with AMI underwent primary PCI. Of these patients, 888 did not have VT/VF (non-VT/VF group) and 116 had sustained VT/VF during prehospitalization or hospitalization. Patients with VT/VF were divided into two groups: early VT/VF (VT/VF occurrence before and within 2 days of admission, 92 patients) and late VT/VF (VT/VF occurrence >2 days after admission; 24 patients) groups.

Results

The frequency of VT/VF occurrence was high between the day of admission and the 2nd day and between days 6 and 10 of hospitalization. The late VT/VF group had a significantly longer onset-to-balloon time, lower ejection fraction, poorer renal function, and higher creatine phosphokinase (CK)-MB level on admission (p< 0.001). They also had a lower 30-day cardiac survival rate than the early VT/VF and non-VT/VF groups (42% vs. 76% vs. 96%, p < 0.001). Moreover, independent predictors of in-hospital cardiac mortality among patients with AMI who had sustained VT/VF were higher peak CK-MB [Odds ratio (OR: 1.001, 95%confidence interval (CI): 1.000-1.002, p= 0.03)], higher Killip class (OR: 1.484, 95%CI 1.017-2.165, p= 0.04), and late VT/VF (OR: 3.436, 95%CI 1.115-10.59, p= 0.03).

Conclusions

The timing of VT/VF occurrences had a bimodal peak. Although late VT/VF occurrence after primary PCI was less frequent than early VT/VF occurrence, patients with late VT/VF had a very poor prognosis.

Impact of out-of-hospital cardiac arrest due to ventricular fibrillation in patients with ST-elevation myocardial infarction admitted for primary percutaneous coronary intervention: Impact of ventricular fibrillation in STEMI patients

OBJECTIVE

Pre-hospital life-threatening ventricular tachycardia/fibrillation (VT/VF) is relatively common in the acute phase of ST-elevation myocardial infarction (STEMI). We evaluated the prognostic impact of out-of-hospital cardiac arrest (OHCA) due to VT/VF in non-selected patients with STEMI admitted for primary percutaneous coronary intervention (PCI).

METHODS

Prospective hospital registry was used to collect data of consecutive STEMI patients admitted to our hospital between 2005 and 2010. Patients with OHCA were identified from this registry, and their medical records were reviewed.

RESULTS

During the study period, 4653 patients were admitted with STEMI. Data regarding OHCA due to VT/VF was available in 4643 patients (99.8%). A total of 326 patients (7.0%) had OHCA due to VT/VF. Patients with OHCA were younger (60.3 ± 11.8 vs. 64.1 ± 12.9 year, p<0.001), less often had diabetes (5.2% vs. 12.4%, p<0.001) but more often presented with signs of heart failure (Killip class >1:17.5% vs. 7.7%, p<0.001) and cardiogenic shock (29.6% vs. 2.5%, p<0.001). Coronary angiography was performed in 97.5% of the patients. Coronary angiography and primary PCI were performed equally in both groups. In patients with OHCA, the left main artery (2.3% vs. 1.0%, p=0.04) and LAD (49.2% vs. 41.2%, p=0.01) were more often the culprit artery. In-hospital mortality was significantly higher among patients with OHCA (13.80% vs. 3.4%, p<0.001). However, in patients who were discharged alive from the hospital, the one-year mortality and the combined incidence of death and appropriate ICD therapy were similar in patients with and without OHCA.

CONCLUSION

In a large non-selected STEMI patient population admitted for primary PCI, OHCA due to VT/VF was associated with higher in-hospital mortality but did not affect the long-term prognosis.

Arrhythmias following revascularization procedures in the course of acute myocardial infarction: are they indicators of reperfusion or ongoing ischemia?

Objective. The most important step in the treatment of ST elevation myocardial infarction is to sustain myocardial blood supply as soon as possible. The two main treatment methods used today to provide myocardial reperfusion are thrombolytic therapy and percutaneous coronary intervention. In our study, reperfusion arrhythmias were investigated as if they are indicators of coronary artery patency or ongoing ischemia after revascularization. Methods. 151 patients with a diagnosis of acute ST elevation myocardial infarction were investigated. 54 patients underwent primary percutaneous coronary intervention and 97 patients were treated with thrombolytic therapy. The frequency of reperfusion arrythmias following revascularization procedures in the first 48 hours after admission was examined. The relation between reperfusion arrhythmias, ST segment regression, coronary artery patency, and infarct related artery documented by angiography were analyzed. Results. There was no statistically significant difference between the two groups in the frequency of reperfusion arrhythmias (P = 0.355). Although angiographic vessel patency was higher in patients undergoing percutaneous coronary intervention, there was no significant difference between the patency rates of each group with and without reperfusion arrythmias. Conclusion. Our study suggests that recorded arrhythmias following different revascularization procedures in acute ST elevation myocardial infarction may not always indicate vessel patency and reperfusion. Ongoing vascular occlusion and ischemia may lead to various arrhythmias which may not be distinguished from reperfusion arrhythmias.

Sustained ventricular tachycardia or fibrillation in the cardiac catheterization laboratory among patients receiving primary percutaneous coronary intervention: incidence, predictors, and outcomes

OBJECTIVES

We sought to evaluate the incidence, predictors, and outcomes of ventricular tachycardia and/or ventricular fibrillation (VT/VF) in the cardiac catheterization laboratory among patients undergoing primary percutaneous coronary intervention (PCI).

BACKGROUND

Although VT/VF has been known to occur during primary PCI, the current data do not identify patients at risk for these arrhythmias or the outcomes of such patients.

METHODS

We evaluated 3065 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI) trials, who underwent primary PCI to evaluate the associations of VT/VF and the influence of these arrhythmias on in-hospital and one-year outcomes.

RESULTS

In patients undergoing primary PCI, VT/VF occurred in 133 (4.3%). Multivariate analysis identified the following as independent correlates of VT/VF: smoking (odds ratio [OR] 1.95, 95% confidence interval [CI] 1.26 to 3.02), lack of preprocedural beta-blockers (OR 2.34, 95% CI 1.35 to 4.07), time from symptom onset to emergency room of <or=180 min (OR 2.63, 95% CI 1.42 to 4.89), initial Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 (OR 2.06, 95% CI 1.23 to 3.47), and right coronary artery-related infarct (OR 1.93, 95% CI 1.25 to 2.99). Although patients with VT/VF had a higher incidence of bradyarrhythmias, hypotension, cardiopulmonary resuscitation, and endotracheal intubation in the catheterization laboratory, their in-hospital and one-year adverse outcomes were similar to those of the cohort without these arrhythmias.

CONCLUSIONS

Our findings suggest that the incidence of VT/VF during primary PCI is low, indicating that these arrhythmias do not influence PCI success or in-hospital or one-year outcomes. Our data further help identify patients at risk of VT/VF during primary PCI and suggest that pretreatment with beta-blockers should be strongly considered to reduce these arrhythmias.

Ventricular arrhythmias in trials of thrombolytic therapy for acute myocardial infarction. A meta-analysis

BACKGROUND

Although thrombolytic therapy reduces long-term mortality in acute myocardial infarction, many clinicians remain concerned about an increased risk of ventricular arrhythmias associated with the use of these agents.

METHODS AND RESULTS

To determine whether thrombolytic therapy increases the risk of ventricular tachyarrhythmias and whether an increase in arrhythmias could be responsible for the increased mortality seen in the first 24 hours after lytic therapy, we performed a meta-analysis of 15 randomized trials of thrombolysis in acute myocardial infarction in which the odds of developing in-hospital ventricular fibrillation (VF) and ventricular tachycardia (VT) in patients receiving thrombolysis was compared with that of patients receiving placebo. For trials that reported the incidence of VF during the first 6 hours after thrombolysis, the summary odds ratio for developing VF in the thrombolytic group was 0.98 (95% confidence interval [CI], 0.6 to 1.6; P = .94). For trials that reported the incidence of VF during the first hospital day, the summary odds ratio for developing VF was 1.00 (95% CI, 0.85 to 1.2; P = .95). The summary odds ratio for the development of VF at any time during hospitalization in the thrombolytic group was 0.83 (95% CI, 0.76 to 0.90; P < .0001). In trials that reported the incidence of VT any time during hospitalization, the summary odds ratio for the development of VT in the thrombolytic group was 1.34 (95% CI, 1.15 to 1.55; P < .0001).

CONCLUSIONS

The likelihood of developing VF in the early hours after thrombolysis for acute myocardial infarction is similar in patients receiving thrombolytics or placebo. However, throughout the hospital course, the risk of VF is greater in patients receiving placebo, whereas the risk of VT is higher in patients receiving thrombolysis.

Incidence and significance of ventricular tachycardia and fibrillation in the absence of hypotension or heart failure in acute myocardial infarction treated with recombinant tissue-type plasminogen activator: results from the Thrombolysis in Myocardial Infarction (TIMI) Phase II trial

OBJECTIVES

The purpose of this study was to determine the incidence of ventricular tachycardia and fibrillation without hypotension or heart failure after treatment with recombinant tissue-type plasminogen activator (rt-PA), anatomic correlates of their development, the effect of immediate intravenous metoprolol on their occurrence and the outcome of patients with these arrhythmias.

BACKGROUND

Malignant arrhythmias after thrombolytic therapy have been reported to occur as a result of coronary reperfusion, which is associated with reduced mortality in patients receiving thrombolytic therapy.

METHODS

We analyzed data from 2,546 patients in the Thrombolysis in Myocardial Infarction (TIMI) Phase II trial without congestive heart failure or hypotension during the 1st 24 h after study entry. Forty-nine patients (1.9%) developed sustained ventricular tachycardia or ventricular fibrillation within 24 h of study entry (group 1), and 2,497 patients (98.1%) did not (group 2).

RESULTS

Baseline characteristics and admission laboratory values were similar in the two groups. In patients undergoing protocol angiography 18 to 48 h after rt-PA, the infarct-related artery was patient in a greater percent of group 2 patients (87% [1,015 of 1,169]) than group 1 patients (68% [15 of 22], p = 0.01), although angiography was performed less frequently in group 1 than in group 2. More group 1 than group 2 patients died within 21 days (20.4%) (1.6%, p < 0.001). For patients surviving to 21 days, there was no difference in mortality between patients in the two groups in the following year.

CONCLUSIONS

Ventricular tachycardia and fibrillation are not markers for reperfusion after thrombolytic therapy. These arrhythmias are associated with occlusion, not patency, of the infarct-related artery. Early mortality is increased in patients who develop ventricular tachycardia and fibrillation, even in the absence of congestive heart failure and hypotension.