M A de Belder

Primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction: changing patterns of vascular access, radial versus femoral artery

Objective: To examine the safety and efficacy of emergency transradial primary percutaneous coronary intervention for ST-elevation myocardial infarction. Design: Single-centre observational study with prospective data collection. Setting: A regional cardiac centre, United Kingdom. Patients: 1051 consecutive patients admitted with ST-elevation myocardial infarction, without cardiogenic shock, between November 2004 and October 2008. Interventions: Percutaneous coronary interventions by radial and femoral access Main outcome measures: The primary outcome measures were procedural success, major vascular complication and failed initial access strategy. Secondary outcomes were in-hospital mortality and major adverse cardiac and cerebrovascular events, needle-to-balloon times, contrast volume used, radiation dose absorbed and time to discharge. Multiple regression analysis was used to adjust for potential differences between the groups. Results: 571 patients underwent radial access and 480 femoral. A variable preference for radial access was observed among the lead operators (between 21% and 90%). Procedural success was similar between the radial and femoral groups, but major vascular complications were more frequent at the site of femoral access (0% radial versus 1.9% femoral, p = 0.001). Failure of the initial access strategy was more frequent in the radial group (7.7% versus 0.6%, p<0.001). Adjustment for other procedural and clinical predictors did not alter these findings. Needle-to-balloon time, as a measure of procedural efficiency, was equal for radial and femoral groups. Conclusions: In the setting of acute ST-elevation myocardial infarction without cardiogenic shock, transradial primary angioplasty is safe, with comparable outcomes to a femoral approach and a lower risk of vascular complications.

Role of non-invasive imaging in the management of coronary artery disease: an assessment of likely change over the next 10 years. A report from the British Cardiovascular Society Working Group

Coronary angiography has been the gold standard for determining the severity, extent and prognosis of coronary atheromatous disease for the past 15–20 years. However, established non-invasive testing (such as myocardial perfusion scintigraphy and stress echocardiography) and newer imaging modalities (multi-detector x ray computed tomography and cardiovascular magnetic resonance) now need to be considered increasingly as a challenge to coronary angiography in contemporary practice. An important consideration is the degree to which appropriate use of such techniques impacts on the need for coronary angiography over the next 10–15 years. This review aims to determine the role of the various investigation techniques in the management of coronary artery disease and their resource implications, and should help determine future service provision, accepting that we are in a period of significant technological change.

Prospective, randomised, controlled trial to study the effect of intracoronary injection of verapamil and adenosine on coronary blood flow during percutaneous coronary intervention in patients with acute coronary syndromes

Objectives: To study the impact of injection of verapamil and adenosine in the coronary arteries on TIMI (Thrombolysis in Myocardial Infarction) frame count (TFC) after percutaneous coronary intervention (PCI) in patients with an acute coronary syndrome (ACS). Methods: Prospective, randomised, controlled study of the intracoronary administration of normal saline versus verapamil versus adenosine in patients undergoing PCI in the setting of an ACS, even when flow is visually established to be normal or near normal. Patients were randomised to receive verapamil (n  =  49), adenosine (n  =  51) or normal saline (n  =  50) after PCI. Quantitative angiography, TIMI flow grade (TFG), TFC and myocardial blush grade were assessed before PCI, after PCI and after drugs were given. Wall motion index (WMI) was measured at days 1 and 30. Results: 9 patients in the verapamil group developed transient heart block, not seen with adenosine (p ⩽ 0.001). Compared with saline, coronary flow measured by TFC improved significantly and WMI improved slightly but insignificantly in both the verapamil (TFC: p  =  0.02; mean difference in improvement in WMI: 0.09, 95% confidence interval (CI) 0.015 to 0.17, p  =  0.02) and the adenosine groups (TFC: p  =  0.002; mean difference in improvement in WMI: 0.08, 95% CI 0.004 to 0.16, p  =  0.04). The improvements in TFC and WMI did not differ significantly between the verapamil and the adenosine groups (TFC: p  =  0.2; mean difference in improvement in WMI: 0.01, 95% CI −0.055 to 0.08, p  =  0.7, respectively). Conclusion: Administration of verapamil or adenosine significantly improves coronary flow and WMI after PCI in the setting of an ACS. Flow and WMI did not differ significantly between verapamil and adenosine but verapamil was associated with the development of transient heart block.

Patterns of coronary artery disease in post-infarction ventricular septal rupture.

Cardiac angiography was reviewed in 91 patients with post-infarction ventricular septal rupture. The results were compared with those of 123 stable survivors who had a positive submaximal exercise test early after infarction. Anterior infarction and occlusion of the infarct vessel were more common in those with ventricular septal rupture than in the comparison group. In the group with ventricular septal rupture there was more left ventricular damage, with aneurysm formation in two thirds, and coronary angiography showed more single than triple vessel disease. In the comparison group there was more triple vessel disease than single vessel disease. Angiographically demonstrable collaterals to the infarct territory were not seen or only very faintly seen in 82% of those with septal rupture. Well developed collaterals were seen in two thirds of the comparison group. These patterns of coronary disease suggest that ventricular septal rupture is more likely in patients with coronary occlusion and little or no collateral support to the infarct territory.

Percutaneous coronary intervention: recommendations for good practice and training

EXECUTIVE SUMMARY: Cardiologists undertaking percutaneous coronary intervention (PCI) are excited by the combination of patient and physician satisfaction and technological advance occurring on the background of the necessary manual dexterity. Progress and applicability of percutaneous techniques since their inception in 1977 have been remarkable; a sound evidence base coupled with the enthusiasm and ingenuity of the medical device industry has resulted in a sea change in the treatment of coronary heart disease (CHD), which continues to evolve at breakneck speed. This is the third set of guidelines produced by the British Cardiovascular Intervention Society and the British Cardiac Society.1,2 Following the last set of guidelines published in 2000, we have seen PCI activity in the UK increase from 33 652 to 62 780 (87% in four years) such that the PCI to coronary artery bypass grafting ratio has increased to 2.5:1. The impact of drug eluting stents has been profound, and the Department of Health is investigating the feasibility of primary PCI for acute myocardial infarction. Nevertheless, the changes in the structure of National Health Service funding are likely to focus our attention on cost effective treatments and will require physician engagement and sensitive handling if we are to continue the rapid and appropriate growth in our chosen field.3 It is important with this burgeoning development now occurring on a broad front (in both regional centres and district general hospitals) that we maintain our vigilance on audit and outcome measures so that standards are maintained for both operators and institutions alike. This set of guidelines includes new sections on training, informed consent, and a core evidence base, which we hope you will find useful and informative. Keith D Dawkins: President, British Cardiovascular Intervention Society (2000–2004) Huon H Gray: President, British Cardiac Society (2003–2005)

Multivariate analysis to simplify the differential diagnosis of broad complex tachycardia.

Univariate analysis has identified several criteria that aid the differential diagnosis of broad complex tachycardia. In this study of 102 consecutive patients multivariate analysis was performed to identify which of 15 clinical and 11 electrocardiographic variables were independent predictors of ventricular tachycardia. These were shown to be a history of myocardial infarction, the QRS waveforms in leads aVF and V1, and a change in axis from sinus rhythm to tachycardia of more than 40 degrees. If none of the criteria was met, the diagnosis was almost certainly supraventricular tachycardia. If one criterion was met the diagnosis was probably supraventricular tachycardia. If two criteria were met then the diagnosis was probably ventricular tachycardia. If three or four criteria were met, the diagnosis was almost certainly ventricular tachycardia. The predictive accuracy was 93%. This was increased to 95% by including two other criteria--definite independent P wave activity and ventricular extrasystoles with the same QRS configuration as that in tachycardia. These criteria were not included in the multivariate analysis because though they were 100% specific they were seldom seen. These four criteria can be used as simple rules in determining the origin of a broad complex tachycardia.

Predictors of outcome after percutaneous treatment for cardiogenic shock

Objectives: To determine predictors of outcome after percutaneous coronary intervention (PCI) in patients with cardiogenic shock complicating acute myocardial infarction. Methods: Retrospective analysis of a cohort of 113 patients undergoing emergency coronary angiography and attempted PCI for cardiogenic shock complicating acute myocardial infarction in a regional cardiothoracic unit. Results: In-hospital mortality was 51% (58 patients). Adverse outcome was associated with previous myocardial infarction, age over 70 years, cardiogenic shock complicating failure to respond to thrombolytic treatment (failed thrombolysis), and multivessel coronary artery disease. Multivariate logistic regression analysis showed that the first three factors were independent predictors of in-hospital death with odds ratios of 5.21 (95% confidence interval (CI) 1.85 to 14.69), 4.02 (95% CI 1.14 to 14.12), and 3.78 (95% CI 1.43 to 9.96), respectively. Conclusion: About 50% of patients with cardiogenic shock undergoing a strategy of urgent coronary angiography and PCI survive to hospital discharge. Survivors do well in the subsequent six months. Emergency PCI for cardiogenic shock reduces mortality from an expected 80% to about 50%. Clinical features can help determine which patients are most likely to gain from urgent coronary angiography and attempted PCI. Alternative strategies are needed to improve the outcome of patients who fare badly.

Failure of thrombolysis by streptokinase: detection with a simple electrocardiographic method

OBJECTIVE To determine whether simple, readily applicable ECG criteria will allow early prediction of inadequate (< TIMI 3) flow in the infarct related vessel in patients receiving thrombolytic treatment for acute myocardial infarction; and to determine the success of streptokinase in achieving adequate antegrade flow in the infarct related vessel two hours after starting treatment. DESIGN Cohort study. SETTING Regional cardiothoracic unit. PATIENTS 100 sequential patients with acute myocardial infarction. INTERVENTIONS Coronary angiography two hours after the initiation of thrombolytic treatment, proceeding to rescue angioplasty for inadequate flow in the infarct related vessel where appropriate. MAIN OUTCOME MEASURES Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of six ECG criteria for the detection of inadequate antegrade flow in the infarct related vessel. RESULTS The ECG test that performed best as a positive test for < TIMI 3 flow in the infarct related vessel was < 50% resolution of the ST segment elevation in the worst lead and no accelerated idioventricular rhythm. This had a sensitivity of 81%, specificity of 88%, positive predictive value of 87%, negative predictive value of 83%, and overall accuracy of 85%. CONCLUSIONS Sensitive, specific, and simple ECG criteria are defined for diagnosing failure of thrombolytic treatment with streptokinase. These allow the early detection of patients at high risk of further adverse events from a persistently occluded vessel. They may be used without recourse to sophisticated equipment or complex analyses. Such patients can then be considered for alternative treatments or enrolment into appropriate research protocols.

Failure of thrombolysis: experience with a policy of early angiography and rescue angioplasty for electrocardiographic evidence of failed thrombolysis

OBJECTIVE To assess the outcome of a policy of emergency coronary angiography with or without rescue angioplasty in patients with acute myocardial infarction and ECG evidence of failed reperfusion after thrombolysis. DESIGN A cohort study. SETTING Regional cardiothoracic unit. PATIENTS 197 patients with acute myocardial infarction fulfilling a simple ECG criterion of failed reperfusion. INTERVENTIONS Emergency coronary angiography proceeding to rescue angioplasty for inadequate antegrade flow. MAIN OUTCOME MEASURES Hospital mortality for all 197 patients; incidence of successful and failed rescue angioplasty; need for additional revascularisation in those receiving rescue angioplasty compared with those not treated in this way. RESULTS 197 patients had emergency angiography for ECG evidence of failed reperfusion; 156 patients received immediate rescue angioplasty. Overall hospital mortality for those undergoing rescue angioplasty was 11.5%. Rescue angioplasty achieved TIMI 2 (11) or TIMI 3 (124) in 135 patients, who had a hospital mortality of 5.9%. Failure to achieve at least TIMI 2 flow following rescue angioplasty occurred in 21 patients, with a hospital mortality of 48%. In the 41 patients in whom immediate rescue angioplasty was not performed, reinfarction or requirement for revascularisation occurred in 37%. Reinfarction occurred in three patients (1.9%) who had immediate rescue angioplasty. Hospital mortality for the whole cohort was 10.7%. CONCLUSIONS A policy of emergency coronary angiography proceeding to rescue angioplasty where appropriate reduces mortality in a high risk group to a level less than expected for patients with acute myocardial infarction and ECG evidence of failed reperfusion. Unsuccessful rescue angioplasty is associated with a high mortality.

One year results of the Middlesbrough early revascularisation to limit infarction (MERLIN) trial

Objective: To report one year results of the MERLIN (Middlesbrough early revascularisation to limit infarction) trial, a prospective randomised trial comparing the strategy of coronary angiography and urgent revascularisation with conservative treatment in patients with failed fibrinolysis complicating ST segment elevation myocardial infarction (STEMI). The 30 day results have recently been published. At the planning stage of the trial, it was determined that follow up of trial patients would continue annually to three years to determine whether late benefit occurred. Subjects: 307 patients who received a fibrinolytic for STEMI but failed to reperfuse early according to previously described ECG criteria and did not develop cardiogenic shock. Methods: Patients were randomly assigned to receive either emergency coronary angiography with a view to proceeding to urgent revascularisation (rescue percutaneous coronary intervention (rPCI) arm) or continued medical treatment (conservative arm). The primary end point was all cause mortality at 30 days. The secondary end points included the composite end point of death, reinfarction, stroke, unplanned revascularisation, or heart failure at 30 days. The same end points were evaluated at one year and these results are presented. Results: All cause mortality at one year was similar in the conservative arm and the rPCI arm (13.0% v 14.4%, p  =  0.7, risk difference (RD) −1.4%, 95% confidence interval (CI) −9.3 to 6.4). The incidence of the composite secondary end point of death, reinfarction, stroke, unplanned revascularisation, or heart failure was significantly higher in the conservative arm (57.8% v 43.1%, p  =  0.01, RD 14.7%, 95% CI 3.5% to 25.5%). This was driven almost exclusively by a significantly higher incidence of subsequent unplanned revascularisation in the conservative arm (29.9% v 12.4%, p < 0.001, RD 17.5%, 95% CI 8.5% to 26.4%). Reinfarction and clinical heart failure were numerically, but not statistically, more common in the conservative arm (14.3% v 10.5%, p  =  0.3, RD 3.8%, 95% CI −3.7 to 11.4, and 31.2% v 26.1%, p  =  0.3, RD 5.0%, 95% CI −5.1 to 15.1). There was a strong trend towards fewer strokes in the conservative arm (1.3% v 5.2%, p  =  0.06, RD −3.9%, 95% CI −8.9 to 0.06). Conclusion: At one year of follow up, there was no survival advantage in the rPCI arm compared with the conservative arm. The incidence of the composite secondary end point was significantly lower in the rPCI arm, but this was driven almost entirely by a highly significant reduction in the incidence of further revascularisation.