Timing, setting and incidence of cardiovascular complications in patients with acute myocardial infarction submitted to primary percutaneous coronary intervention

Complete Atrioventricular Block and Permanent Pacemaker Implantation Following Percutaneous Coronary Intervention to Left Anterior Descending Artery Chronic Total Occlusion

A 72-year-old male patient, with first degree atrioventricular block and LBBB on his baseline ECG, developed persistent complete atrioventricular block after recanalization of a chronic total occlusion of his left anterior descending artery (LAD) and ultimately underwent permanent pacemaker implantation. Occlusion of the second septal branch, probably supplying the right branch of the His bundle is speculated to have led to this complication. During elective intervention to the LAD territory in patients with prior conduction abnormalities on the ECG, care should be taken to preserve normal blood flow to the septal perforators. When a deterioration in septal perfusion occurs restoration of flow by wiring and balloon dilatation should be considered.

In-hospital major arrhythmias, arrhythmic death and resuscitation after successful primary percutaneous intervention for acute transmural infarction: a retrospective single-centre cohort study

BACKGROUND

Transmural acute myocardial infarction (AMI) is associated with a high risk for ventricular arrhythmia before, during and after treatment. Consequently, it is recommended that patients diagnosed with transmural AMI be monitored in a cardiac care unit (CCU) so life-threatening arrhythmias can be treated promptly. We examined the incidence and timing of in-hospital malignant ventricular arrhythmias, sudden cardiac or arrhythmic death (SCD/AD) and resuscitation requirements in patients with transmural AMI recovering from percutaneous coronary intervention (PCI) undertaken within 12 h of symptom onset and without antecedent thrombolysis.

METHODS

This was a retrospective cohort study using the Duisburg Heart Center (Germany) cardiac patient registry. In total, 975 patients met the inclusion criteria. The composite endpoint was post-PCI ventricular fibrillation or tachycardia, SCD/AD or requirement for resuscitation. We compared the demographic and clinical characteristics of patients who met the composite endpoint with those who did not, recorded the timing of endpoint episodes, and used multivariable logistic regression analysis to identify factors associated with the endpoint criteria.

RESULTS

There was no significant difference in the length of CCU or hospital stay between the groups. In-hospital mortality was 6.5%, and the composite endpoint was met in 7.4% of cases. Malignant ventricular tachyarrhythmia occurred in 2.8% of the patients, and SCD/AD occurred in 0.3% of the cases. There was a biphasic temporal distribution of endpoint events; specifically, 76.7% occurred < 96 h after symptom onset, and 12.6% occurred 240-360 h after symptom onset. Multivariable regression analysis identified positive associations between an endpoint episode and the following: age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05] per year); left ventricular ejection fraction (LVEF) < 30% (OR 3.66, 95% CI 1.91-6.99); peak serum creatine phosphokinase concentration (OR 1.01, 95% CI 1.00-1.02 per 100 U/dl); leucocytosis (OR 1.86, 95% CI 1.04-3.32), and coronary thrombus (OR 1.85, 95% CI 1.04-3.27).

CONCLUSIONS

Most post-PCI malignant ventricular arrhythmias, SCD/AD and resuscitation episodes occurred within 96 h of transmural AMI (76.7%). A substantial minority (12.6%) of these events arose 240-360 h after symptom onset. Further study is needed to establish the influence of age, LVEF < 30%, peak serum creatine phosphokinase concentration, leucocytosis and coronary thrombus on post-PCI outcomes after transmural AMI.

Periprocedural temporary pacing in primary percutaneous coronary intervention for patients with acute inferior myocardial infarction

OBJECTIVE

High-degree atrioventricular block (AVB), including complete AVB in acute inferior ST-elevation myocardial infarction (STEMI), is not uncommon. However, there is no study evaluating the clinical differences between patients who have undergone temporary pacing (TP) and patients who have not. The present study was designed to investigate whether TP has any prognostic significance in inferior STEMI complicated by complete AVB.

METHODS

From January 2009 to December 2014, 295 consecutive patients diagnosed with inferior wall STEMI in a university hospital were reviewed. All of them underwent primary percutaneous coronary intervention (PCI). Among the 295 patients, there were 72 patients with complete AVB. The clinical characteristics, procedural data, and long-term major adverse cardiocerebrovascular events were compared in patients with and without TP.

RESULTS

Baseline clinical and procedural characteristics were similar between patients with and without TP. Patients with TP were more likely to present with cardiogenic shock; thus, additional interventions were attempted via a femoral approach, as patients received further treatment with intra-aortic balloon pumps and were subjected to additional cardiopulmonary resuscitation. Most cases of complete AVB were primarily caused by right coronary artery occlusion. After a median follow-up period of 344 (range, 105.5-641) days, major adverse cardiocerebrovascular events did not differ between the groups (P=0.528).

CONCLUSION

We conclude that primary PCI without TP is acceptable in complete AVB-complicated acute inferior STEMI. To avoid delay in reperfusion, we suggest that primary PCI should be the first priority therapy rather than treating patients initially with TP.

Reversibility of High-Grade Atrioventricular Block with Revascularization in Coronary Artery Disease without Infarction: A Literature Review

Complete atrioventricular (AV) block is known to be reversible in some cases of acute inferior wall myocardial infarction (MI). The reversibility of high-grade AV block in non-MI coronary artery disease (CAD), however, is rarely described in the literature. Herein we perform a literature review to assess what is known about the reversibility of high-grade AV block after right coronary artery revascularization in CAD patients who present without an acute MI. To illustrate this phenomenon we describe a case of 2 : 1 AV block associated with unstable angina, in which revascularization resulted in immediate and durable restoration of 1 : 1 AV conduction, thereby obviating the need for permanent pacemaker implantation. The literature review suggests two possible explanations: a vagally mediated response or a mechanism dependent on conduction system ischemia. Due to the limited understanding of AV block reversibility following revascularization in non-acute MI presentations, it remains difficult to reliably predict which patients presenting with high-grade AV block in the absence of MI may have the potential to avoid permanent pacemaker implantation via coronary revascularization. We thus offer this review as a potential starting point for the approach to such patients.

Association of Admission Glycaemia With High Grade Atrioventricular Block in ST-Segment Elevation Myocardial Infarction Undergoing Reperfusion Therapy: An Observational Study

Several studies have demonstrated the association between elevated admission glycaemia (AG) and the occurrence of some arrhythmias such as atrial fibrillation, ventricular tachycardia, and ventricular fibrillation after myocardial infarction. However, the impact of elevated AG on the high grade atrioventricular block (AVB) occurrence after ST-segment elevation myocardial infarction (STEMI) remains unclear. Included were 3359 consecutive patients with STEMI who received reperfusion therapy. The primary endpoint was the development of high grade AVB during hospital course. Patients were divided into non-diabetes mellitus (DM), newly diagnosed DM, and previously known DM according to the hemoglobin A1c level. The optimal AG value was determined by receiver operating characteristic curves analysis with AG predicting the high grade AVB occurrence. The best cut-off value of AG for predicting the high grade AVB occurrence was 10.05 mmol/L by ROC curve analysis. The prevalence of AG ≥ 10.05 mmol/L in non-DM, newly diagnosed DM, and previously known DM was 15.7%, 34.1%, and 68.5%, respectively. The incidence of high grade AVB was significantly higher in patients with AG ≥ 10.05  mmol/L than <10.05  mmol/L in non-DM (5.7% vs. 2.1%, P < 0.001) and in newly diagnosed DM (10.2% vs.1.4%, P < 0.001), but was comparable in previously known DM (3.6% vs. 0.0%, P = 0.062). After multivariate adjustment, AG ≥ 10.05  mmol/L was independently associated with increased risk of high grade AVB occurrence in non-DM (HR = 1.826, 95% CI 1.073-3.107, P = 0.027) and in newly diagnosed DM (HR = 5.252, 95% CI 1.890-14.597, P = 0.001). Moreover, both AG ≥ 10.05  mmol/L and high grade AVB were independent risk factors of 30-day all cause-mortality (HR = 1.362, 95% CI 1.006-1.844, P = 0.046 and HR = 2.122, 95% CI 1.154-3.903, P = 0.015, respectively). Our study suggested that elevated AG level (≥10.05  mmol/L) might be an indicator of increased risk of high grade AVB occurrence in patients with STEMI.

Primary percutaneous coronary intervention ameliorates complete atrioventricular block complicating acute inferior myocardial infarction

Objective

Complete atrioventricular block (CAVB) in acute inferior ST-segment elevation myocardial infarction (STEMI) is associated with poor clinical outcomes after noninvasive treatment. This study was designed to determine the effect of primary percutaneous coronary intervention (PCI) in patients with CAVB complicating acute inferior STEMI, at a single center.

Methods

We enrolled 138 consecutive patients diagnosed with STEMI involving the inferior wall; of these, 27 patients had CAVB. All patients received primary PCI. The clinical characteristics, procedural data, and clinical outcomes were compared in patients with versus without CAVB.

Results

Baseline clinical characteristics were similar between patients with and without CAVB. Patients with CAVB were more likely to present with cardiogenic shock, and CAVB was caused primarily by right coronary artery occlusion. Door-to-balloon time was similar between those two groups. After primary PCI, CAVB was reversed in all patients. The peak creatinine phosphokinase level, left ventricular ejection fraction and in-hospital mortality rate were similar between the two groups. After a median follow up of 318 days, major adverse cardiac events did not differ between the groups (8.1% in patients without CAVB; 11.1% in patients with CAVB) (P=0.702).

Conclusion

We conclude that primary PCI can ameliorate CAVB-complicated acute inferior STEMI, with an acceptable rate of major adverse cardiac events, and suggest that primary PCI should be the preferred reperfusion therapy in patients with CAVB complicating acute inferior myocardial infarction.

Reversibility of atrioventricular block according to coronary artery disease: results of a retrospective study

Background and Objectives

The causal relationship of clinically-significant atrioventricular block (AVB) and coronary artery disease (CAD) is uncertain. We investigated whether CAD is related to irreversible AVB that requires treatment with a permanent pacemaker.

Subjects and Methods

We included 188 consecutive patients with new-onset AVB considering pacemaker, who had undergone invasive or noninvasive coronary evaluation. Patients were divided into one of 2 groups: irreversible AVB who underwent implantation of permanent pacemaker {irreversible block (IB) group, n=173} or reversible AVB {reversible block (RB) group, n=15}.

Results

In IB group, significant CAD was observed in 44 patients (25.4%) and there were 2 (1.2%) patients with acute myocardial infarction (AMI). In RB group, 14 patients (93.3%) had CAD (p<0.001) and 13 patients (86.7%) presented with AMI (p<0.001). On the aspect of CAD type and reversibility of AVB, 13/15 (86.7%) patients of AMI, 0/2 (0%) of unstable angina, and 1/41 (2.4%) of stable angina had reversible AVB.

Conclusion

AVB in patients with AMI is usually reversible. Therefore, permanent pacemaker implantation should be delayed in cases of AMI. AVB in patients with CAD other than AMI is usually irreversible.

Percutaneous coronary intervention delays pacemaker implantation in coronary artery disease patients with established bradyarrhythmias

BACKGROUND

Pacemakers have long been used to assist the heart under pathological conditions, and they are the first choice in the treatment of systematic bradyarrhythmias. However, the effect of percutaneous coronary intervention (PCI) in patients with coronary artery disease as well as bradyarrhythmias remains unknown.

METHODS

In the present study, 42 patients with chest pain and/or abnormal stress test results were surveyed. Before coronary angiography, patients underwent complete examination, including a 24 h dynamic electrocardiogram, which was used to diagnose bradyarrhythmias that were not suitable for pacemaker implantation due to a lack of arrhythmia-related symptoms. All patients underwent PCI but did not undergo pacemaker implantation. Forty-one patients with chest pain and/or abnormal stress test results, as well as symptom-free bradyarrhythmias, were selected as the control group. All of the patients in the control group were committed to treatments without PCI.

RESULTS

During a mean (±SD) of 3.3±0.5 years of follow-up (range 2.5 to 4.5 years), 24 of 42 patients who received PCI underwent pacemaker implantation for arrhythmia-related symptoms, eight were shown by Holter monitoring to have worsened but still exhibited no symptoms, and the remainder did not show any changes according to the examinations performed. In the control group, 31 patients underwent pacemaker implantation for arrhythmia-related symptoms, eight were shown by Holter monitoring to have worsened but still exhibited no symptoms, and two did not show any changes according to the examinations performed. Nevertheless, the rates of pacemaker implantation each year (from the first to the third year) between the two groups were 7.1% versus 39.0% (P=0.001); 33.3% versus 63.4% (P=0.006); and 57.1% versus 75.6%, (P=0.075), respectively.

CONCLUSIONS

The present study found that PCI delayed the demand for pacemaker implantation among coronary artery disease patients.

Post myocardial infarction cardiogenic shock: a review of current therapies

Cardiogenic shock is often a devastating consequence of acute myocardial infarction (MI) and portends to significant mortality and morbidity. Despite improvements in expediting the time to treatment and enhancements in available medical therapy and reperfusion techniques, cardiogenic shock remains the most common cause of mortality following MI. Post-MI cardiogenic shock most commonly occurs as a consequence of severe left ventricular dysfunction. Right ventricular (RV) MI must also be considered. Mechanical complications including acute mitral regurgitation, ventricular septal rupture, and ventricular free-wall rupture can also lead to cardiogenic shock. Rapid diagnosis of cardiogenic shock and its underlying cause is pivotal to delivering definitive therapy. Intravenous vasoactive agents and mechanical support devices may temporize the patient's hemodynamic status until definitive therapy by percutaneous or surgical intervention can be performed. Despite prompt management, post-MI cardiogenic shock mortality remains high.

Role of hemodynamic shear stress in cardiovascular disease

Atherosclerosis is the main cause of morbidity and mortality in the Western world. Inflammation and blood flow alterations are new markers emerging as possible determinants for the development of atherosclerotic lesions. In particular, blood flow exerts a shear stress on vessel walls that alters cell physiology. Shear stress arises from the friction between two virtual layers of a fluid and is induced by the difference in motion and viscosity between these layers. Regions of the arterial tree with uniform geometry are exposed to a unidirectional and constant flow, which determines a physiologic shear stress, while arches and bifurcations are exposed to an oscillatory and disturbed flow, which determines a low shear stress. Atherosclerotic lesions develop mainly in areas of low shear stress, while those exposed to a physiologic shear stress are protected. The presence of areas of the arterial tree with different wall shear stress may explain, in part, the different localization of atherosclerotic lesions in both coronary and extracoronary arteries. The measurement of this parameter may help in identifying atherosclerotic plaques at higher risk as well as in evaluating the efficacy of different pharmacological interventions. Moreover, an altered shear stress is associated with the occurrence of both aortic and intracranial aneurysms, possibly leading to their growth and rupture. Finally, the evaluation of shear stress may be useful for predicting the risk of developing restenosis after coronary and peripheral angioplasty and for devising a coronary stent with a strut design less thrombogenic and more conducive to endothelization.

Air ambulance transport times and advanced cardiac life support interventions during the interfacility transfer of patients with acute ST-segment elevation myocardial infarction

OBJECTIVES

To characterize transport times for the interfacility air ambulance transport of patients with acute ST-segment elevation myocardial infarction (STEMI), to estimate the proportion of patients at risk of in-transport clinical decompensation, and to explore associated risk factors for such.

METHODS

The electronic medical records of 35 air ambulance programs in the United States from December 2003 through December 2008 were reviewed. We defined clinical decompensation during transport as the combined outcome of either cardiopulmonary arrest or the receipt of any of a prespecified set of advanced life support (ALS) interventions. Multiple logistic regression employing generalized estimating equations to model autocorrelation of measures within air ambulance programs was used to explore the relationship between time from dispatch to transport and the outcome of interest.

RESULTS

Three thousand seven hundred sixty-seven transports of STEMI patients were identified during the period of interest. Eighty-five percent of rotor wing transports (median 80 minutes, interquartile range [IQR] 66-104) and 7% of fixed-wing transports (median 162 minutes, IQR 142-210) attained a total transfer time of < or = 2 hours. Clinical decompensation in transport occurred in 182 of 3,767 (4.8%, 95% confidence interval [CI] 4.2-5.6%) transports. The most frequent critical ALS interventions were the administration of antiarrhythmics and the initiation of vasopressors. The odds ratios (ORs) for clinical decompensation comparing higher pretransport time quartiles with the lowest quartile (i.e., Q1: 6-50 minutes) were as follows: Q4: 82-1,500 minutes, OR 2.5 (95% CI 1.3-4.8, p = 0.007); Q3: 64-81 minutes, OR 1.9 (95% CI 1.0-3.6, p = 0.0499); and Q2: 51-63 minutes, OR 1.45 (95% CI 0.7-3.1, p = 0.34). Cardiac arrest or need for an ALS intervention prior to transport and a history of diabetes were also predictive of the outcome of interest.

CONCLUSIONS

The majority of interfacility rotor-wing air ambulance transfers of patients with STEMI achieved a total transfer time of < or = 2 hours. Clinical decompensation requiring ALS treatment occurred in a small percentage of patients. Diabetes, prior arrest or decompensation, and delays to transport were associated with clinical decompensation in the air. Efforts to reduce delays to transport may reduce this risk in transported patients.

Primary percutaneous coronary intervention in comatose survivors of cardiac arrest with ST-elevation acute myocardial infarction: a single-center experience in Florence

OBJECTIVE

Primary percutaneous coronary intervention is currently known as the most effective reperfusion strategy in patients with ST-elevation myocardial infarction. There are no formal recommendations from the American Heart Association/American College of Cardiology and European Society of Cardiology guidelines regarding the treatment of comatose patients with signs of ST-elevation myocardial infarction after reestablishment of spontaneous circulation.

METHODS

We assessed prognosis in 31 consecutive comatose ST-elevation myocardial infarction patients admitted to our intensive cardiac care unit after early percutaneous coronary intervention from 1 January 2005 to 30 June 2006.

RESULTS

During intensive cardiac care unit stay, eight patients died (8/23, 34.7%). In comparison between patients who died and those who survived, the former were older (P = 0.049), showed a higher incidence of chronic obstructive pulmonary disease and had a shorter intensive cardiac care unit length of stay (P = 0.001). No differences were detectable in the two subgroups regarding angiographic characteristics. The incidence of thrombolysis in myocardial infarction grade 3 postpercutaneous coronary intervention was higher in patients who survived (P = 0.0437). Patients who died showed higher latency times, both symptoms-to-basic life support and symptoms-emergency-team (P = 0.0171 and 0.0116, respectively). Patients who survived showed a higher ejection fraction than those who died, as well as lower values of peak troponin I, leukocytes and glycemia (P = 0.01, 0.001 and 0.05, respectively).

CONCLUSION

According to our data, comatose survivors undoubtedly present a high-risk subgroup of ST-elevation myocardial infarction population in which percutaneous coronary intervention shows a procedural efficacy similar to conscious ST-elevation myocardial infarction patients and whose prognosis seems to be related both to infarct size and to neurological status. Further studies need to be performed in this high-risk subgroup investigating the effects of mild hypothermia (mainly on the neurological outcome) as well as the feasibility, safety and outcome of assistance device.