Routine invasive strategies versus selective invasive strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

People with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) are managed with a combination of medical therapy, invasive angiography and revascularisation. Specifically, two approaches have evolved: either a 'routine invasive' strategy whereby all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularisation; or a 'selective invasive' (also referred to as 'conservative') strategy in which medical therapy alone is used initially, with a selection of patients for angiography based upon evidence of persistent myocardial ischaemia. Uncertainty exists as to which strategy provides the best outcomes for these patients. This Cochrane review is an update of a Cochrane review originally published in 2006, to provide a robust comparison of these two strategies in the early management of patients with UA/NSTEMI.

OBJECTIVES

To determine the benefits and harms associated with the following.1. A routine invasive versus a conservative or 'selective invasive' strategy for the management of UA/NSTEMI in the stent era.2. A routine invasive strategy with and without glycoprotein IIb/IIIa receptor antagonists versus a conservative strategy for the management of UA/NSTEMI in the stent era.

SEARCH METHODS

We searched the following databases and additional resources up to 25 August 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE and EMBASE, with no language restrictions.

SELECTION CRITERIA

We included prospective randomised controlled trials (RCTs) that compared invasive with conservative or 'selective invasive' strategies in participants with acute UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

Two review authors screened the records and extracted data in duplicate. Using intention-to-treat analysis with random-effects models, we calculated summary estimates of the risk ratio (RR) with 95% confidence intervals (CIs) for the primary endpoints of all-cause death, fatal and non-fatal myocardial infarction (MI), combined all-cause death or non-fatal MI, refractory angina and re-hospitalisation. We performed further analysis of included studies based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. We assessed the heterogeneity of included trials using Pearson χ² (Chi² test) and variance (I² statistic) analysis. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 (Review Manager) to create Summary of findings (SoF) tables.

MAIN RESULTS

Eight RCTs with a total of 8915 participants (4545 invasive strategies, 4370 conservative strategies) were eligible for inclusion. We included three new studies and 1099 additional participants in this review update. In the all-study analysis, evidence did not show appreciable risk reductions in all-cause mortality (RR 0.87, 95% CI 0.64 to 1.18; eight studies, 8915 participants; low quality evidence) and death or non-fatal MI (RR 0.93, 95% CI 0.71 to 1.2; seven studies, 7715 participants; low quality evidence) with invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. There was appreciable risk reduction in MI (RR 0.79, 95% CI 0.63 to 1.00; eight studies, 8915 participants; moderate quality evidence), refractory angina (RR 0.64, 95% CI 0.52 to 0.79; five studies, 8287 participants; moderate quality evidence) and re-hospitalisation (RR 0.77, 95% CI 0.63 to 0.94; six studies, 6921 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies also at six to 12 months follow-up.Evidence also showed increased risks in bleeding (RR 1.73, 95% CI 1.30 to 2.31; six studies, 7584 participants; moderate quality evidence) and procedure-related MI (RR 1.87, 95% CI 1.47 to 2.37; five studies, 6380 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies.The low quality evidence were as a result of serious risk of bias and imprecision in the estimate of effect while moderate quality evidence was only due to serious risk of bias.

AUTHORS' CONCLUSIONS

In the all-study analysis, the evidence failed to show appreciable benefit with routine invasive strategies for unstable angina and non-ST elevation MI compared to conservative strategies in all-cause mortality and death or non-fatal MI at six to 12 months. There was evidence of risk reduction in MI, refractory angina and re-hospitalisation with routine invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. However, routine invasive strategies were associated with a relatively high risk (almost double the risk) of procedure-related MI, and increased risk of bleeding complications. This systematic analysis of published RCTs supports the conclusion that, in patients with UA/NSTEMI, a selectively invasive (conservative) strategy based on clinical risk for recurrent events is the preferred management strategy.

First Australian transapical mitral valve-in-valve implant for a failed mitral bioprosthesis: how to do it

Transcatheter aortic valve replacements lower mortality in patients not suitable for surgical valve replacement compared to conservative treatment. Transcatheter valve-in-valve implants have been shown to be feasible in failed bioprostheses in aortic, mitral, pulmonary and tricuspid positions. We report the first Australasian experience of a transapical mitral valve-in-valve placement with an Edwards Sapien(®) transcatheter valve for a failed mitral bioprosthesis, focussing on the technical aspects of this novel procedure. Whilst the evidence for this niche indication is limited currently to case reports and case series, further evaluation of its long term outcomes may justify its use in this particularly high risk group of re-do sternotomy patients.

Early invasive versus conservative strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) two strategies are possible, either a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially, with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE and EMBASE were searched (1996 to February 2008) with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified five studies (7818 participants). Using intention-to-treat analysis with random-effects models, summary estimates of relative risk (RR) with 95% confidence interval (CI) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction, all-cause death or non-fatal myocardial infarction, and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using Chi(2) and variance (I(2) statistic) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy (RR 1.59, 95% CI 0.96 to 2.64). The invasive strategy did not reduce death on longer-term follow up. Myocardial infarction rates assessed at 6 to 12 months (5 trials) and 3 to 5 years (3 trials) were significantly decreased by an invasive strategy (RR 0.73, 95% CI 0.62 to 0.86; and RR 0.78, 95% CI 0.67 to 0.92 respectively). The incidence of early (< 4 month) and intermediate (6 to 12 month) refractory angina were both significantly decreased by an invasive strategy (RR 0.47, 95% CI 0.32 to 0.68; and RR 0.67, 95% CI 0.55 to 0.83 respectively), as were early and intermediate rehospitalization rates (RR 0.60, 95% CI 0.41to 0.88; and RR 0.67, 95% CI 0.61 to 0.74 respectively). The invasive strategy was associated with a two-fold increase in the RR of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the RR of (minor) bleeding with no hazard of stroke.

AUTHORS' CONCLUSIONS

Compared to a conservative strategy for UA/NSTEMI, an invasive strategy is associated with reduced rates of refractory angina and rehospitalization in the shorter term and myocardial infarction in the longer term. However, the invasive strategy is associated with a doubled risk of procedure-related heart attack and increased risk of bleeding and procedural biomarker leaks. Available data suggest that an invasive strategy may be particularly useful in those at high risk for recurrent events.

High-dose tirofiban with enoxaparin and inflammatory markers in high-risk percutaneous intervention

AIM

The study assessed the benefit of high bolus dose tirofiban (HD-tirofiban) with enoxaparin compared with HD-tirofiban with unfractionated heparin (UFH). The study examined markers of platelet activation, thrombin generation and inflammation.

MATERIALS AND METHODS

The study is a prospective single centre open-label trial of patients with high-risk acute coronary syndrome treated with percutaneous intervention (PCI) who were randomized to anticoagulation with UFH or enoxaparin with HD-tirofiban (25 microg kg(-1) bolus). This study measured a panel of platelet activation markers, inflammatory biomarkers and thrombus generation between the two groups.

RESULT

Sixty patients undergoing high-risk PCI were enroled in the study. Platelet inhibition as assessed by whole blood aggregometry following HD-tirofiban infusion was similar in both the UFH and enoxaparin groups. CD40 ligand expression on platelets was significantly reduced following PCI with HD-tirofiban and either UFH or enoxaparin. Following PCI, there were significant reductions measured in other markers of platelet activation including PAC-1, P selectin, factor V/Va, platelet-monocyte aggregates and monocyte expression of Mac-1 as determined by analysis of venous blood samples using flow cytometry. Prothrombin fragment 1+2, D-dimer, von Willebrand factor and high sensitive C-reactive protein levels were significantly less post PCI in the enoxaparin group compared with those patients receiving UFH.

CONCLUSION

The combination of HD tirofiban with enoxaparin resulted in an attenuated inflammatory response when compared with that of the combination of HD tirofiban with UFH.

Variations in the application of cardiac care in Australia

OBJECTIVE

To evaluate the use of clinical practice guidelines for the management of acute coronary syndromes published by the National Heart Foundation (NHF) of Australia and the Cardiac Society of Australia and New Zealand (CSANZ) in patients presenting with chest pain.

DESIGN

Cross-sectional study of consecutive patients admitted with chest pain.

SETTING

Prospective case note review was undertaken in 2380 patients admitted to 27 hospitals across five states in Australia between January 2003 and August 2005. Patients were divided into two groups: those who presented to centres with angiography and percutaneous intervention facilities (n = 1260) and those treated at centres without these facilities (n = 1120).

MAIN OUTCOME MEASURES

The proportion of patients whose care met quality of care standards for diagnostic and risk-stratification procedures and management according to NHF/CSANZ treatment guidelines.

RESULTS

Significant delays were identified in performing electrocardiography, administering thrombolysis, transferring high-risk patients to tertiary centres, and performing revascularisation. Medical therapy was underused, especially glycoprotein IIb/IIIa antagonists in patients with high-risk acute coronary syndromes. Patients treated at centres without interventional facilities were less likely to receive guidelines-based medical therapy and referral for coronary angiography (20.11%) than patients treated at centres with interventional facilities (66.43%; P < 0.001).

CONCLUSION

There are deficits in the implementation and adherence to evidence-based guidelines for managing chest pain in hospitals across Australia, and significant differences between hospitals with and without interventional facilities.

Early invasive versus conservative strategies for unstable angina & non-ST-elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST-elevation myocardial infarction (UA/NSTEMI) two strategies are possible: a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to a conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (Issue 3 2005), MEDLINE and EMBASE were searched from 1996 to September 2005 with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified 5 studies (7818 participants). Using intention-to-treat analysis with random effects models, summary estimates of relative risk (95% confidence interval [CI]) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction; all-cause death or non-fatal myocardial infarction; and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using chi-square and variance (I(2)) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy; relative risk 1.59 (95% CI 0.96 to 2.64). Mortality and myocardial infarction assessed at 2-5 years in two trials were significantly decreased by an invasive strategy with relative risk of 0.75 (95% CI 0.62 to 0.92) and 0.75 (95% CI 0.61 to 0.91) respectively. The composite end-point of death or non-fatal myocardial infarction was significantly decreased by an invasive strategy at several time points after initial hospitalization. The incidence of early (<4 months) and intermediate (6-12 months) refractory angina were both significantly decreased by an invasive strategy; relative risk 0.47 (95% CI 0.32 to 0.68) and 0.67 (95% CI 0.55 to 0.83) respectively, as were early and intermediate rehospitalization rates with relative risk 0.60 (95% CI 0.41 to 0.88) and 0.67 (95% CI 0.61 to 0.74) respectively. The invasive strategy was associated with a two-fold increase in the relative risk of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the relative risk of bleeding.

AUTHORS' CONCLUSIONS

An early invasive strategy is preferable to a conservative strategy in the treatment of UA/NSTEMI.

Measurement of Myocardial Fractional Flow Reserve is a Cost-effective Way to Identify Coronary Artery Lesions of Indeterminate Severity that Warrant Revascularisation

BACKGROUND

The RADI pressure wire may be used in stenotic coronary arteries to calculate myocardial fractional flow reserve (FFR(myo)), the ratio between distal hyperaemic coronary pressure and aortic pressure. A ratio less than 0.75 categorizes lesions of haemodynamic significance for which percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) may be warranted. We undertook this study to evaluate the cost implications of performing these measurements.

METHODS

We recorded FFR(myo) using RADI wires in 32 coronary artery lesions of between 30 and 60% diameter stenosis in 31 patients and assessed how this information changed our management.

RESULTS

We followed our original "management plan" in only eight patients. PCI or CABG was performed in eight whose lesions were characterised by a FFR(myo) value of 0.76 or less. Myocardial perfusion imaging (MPI) was done in only one of nine for whom this had seemed to be appropriate. Two-thirds of those for whom PCI had appeared to be warranted were treated conservatively and only one quarter of the original "surgical" group underwent CABG.

CONCLUSION

Although RADI pressure wires are an additional expense, it is appropriate to use them to assess coronary stenotic lesions of indeterminate severity. When we took into account the savings that arose from changes in management, the additional cost of measuring FFR(myo) was around dollar 580 per study.

National data elements for the clinical management of acute coronary syndromes

Patients with acute coronary syndromes represent a clinically diverse group and their care remains heterogeneous. These patients account for a significant burden of morbidity and mortality in Australia. Optimal patient outcomes depend on rapid diagnosis, accurate risk stratification and the effective implementation of proven therapies, as advocated by clinical guidelines. The challenge is in effectively applying evidence in clinical practice. Objectivity and standardised quantification of clinical practice are essential in understanding the evidence-practice gap. Observational registries are key to understanding the link between evidence-based medicine, clinical practice and patient outcome. Data elements for monitoring clinical management of patients with acute coronary syndromes have been adapted from internationally accepted definitions and incorporated into the National Health Data Dictionary, the national standard for health data definitions in Australia. Widespread use of these data elements will assist in the local development of "quality-of-care" initiatives and performance indicators, facilitate collaboration in cardiovascular outcomes research, and aid in the development of electronic data collection methods.

Platelet–monocyte aggregates predict troponin rise after percutaneous coronary intervention and are inhibited by Abciximab

BACKGROUND

Platelet-monocyte aggregates and other markers of platelet activation were investigated before and after percutaneous coronary intervention (PCI) with abciximab therapy. The study sought to assess the relationship between the level of platelet-monocyte aggregation and increases in cardiac troponin I post coronary intervention.

METHODS

Blood samples were collected from 40 patients before PCI and 10 min after abciximab administration. These were tested for platelet activation markers by flow cytometry. Cardiac troponin I levels were assayed at baseline and at 24 h post PCI.

RESULTS

Compared to healthy controls, patients with coronary artery disease had elevated markers of platelet activation including platelet-monocyte aggregates, P-selectin and PAC-1 (a marker specific for activated glycoprotein IIb/IIIa) prior to PCI. Increased levels of platelet-monocyte aggregates before PCI were associated with increased expression of P-selectin on the platelet surface. Abciximab therapy reduced platelet-monocyte aggregate levels but had no effect on P-selectin expression. The high levels of expression of activated glycoprotein IIb/IIIa (PAC-1) on platelets prior to PCI was reduced with abciximab therapy. Patients with higher levels of platelet-monocyte aggregates prior to PCI were more likely to develop an elevation of cardiac troponin I during the 24 h after PCI.

CONCLUSIONS

Increased levels of platelet-monocyte aggregates may predict patients at risk for troponin elevation following PCI and identify those most likely to benefit from abciximab.

Failure of current public educational campaigns to impact on the initial response of patients with possible heart attack

AIMS

The National Heart Foundation of Australia recognizes that the risk of lethal arrhythmias is greater very early after the onset of myocardial infarction and that the more promptly flow can be restored in the infarct-related artery the greater will be the benefits for survival and preservation of heart function. The Heart Foundation has therefore conducted several public media campaigns to encourage patients to seek help more promptly and evaluated their impact.

METHODS

Since 1996, we have conducted four surveys of delays preceding admission of patients to coronary care units throughout Australia to assess the impact of the Heart Foundation's media campaigns. Data were collected on 1665 patients who presented to 73 hospitals; information on patient delay was available for 1178 of them.

RESULTS

There were no significant differences in patient delay (median 1.5-2.0 h) in the four surveys from 1996 to 2002, nor when patients were categorized by age, sex, presenting diagnosis or history of previous myocardial infarction or coronary revascularization by percutaneous or surgical techniques.

CONCLUSION

New approaches are needed to reduce patient-related delay after the onset of symptoms suggesting possible myocardial infarction.

Ventricular septal rupture following nonsurgical septal reduction for hypertrophic cardiomyopathy: Treatment with percutaneous closure

An 82-year-old woman with severe symptomatic hypertrophic obstructive cardiomyopathy undergoes nonsurgical septal reduction, leading to immediate hemodynamic and functional improvement. Five weeks later, she presents with severe biventricular failure due to a large septal rupture with marked left-to-right shunting. The rupture is closed with an Amplatzer post-MI ventricular septal defect occluding device. Residual shunting through the device and a small residual shunt at its superior rim lead to severe hemolysis, which resolves spontaneously after 10 days of supportive therapy. A further self-limiting episode of hemolysis recurred 3 months later following a period of excessive anticoagulation.

A new technique to guarantee access to the sidebranch during bifurcational coronary stenting

Two consecutive patients are treated using a new technique whereby a stent is implanted across a sidebranch but access to the sidebranch is never lost, thereby guaranteeing further treatment with balloon dilatation or stenting as required.

Lack of effect of coenzyme Q on left ventricular function in patients with congestive heart failure

OBJECTIVES

This study evaluated the effects of oral therapy with coenzyme Q on echocardiographic and hemodynamic indexes of left ventricular function and on quality of life in patients with chronic left ventricular dysfunction.

BACKGROUND

Coenzyme Q is a coenzyme for oxidative phosphorylation and an antioxidant and free radical scavenger. It has been claimed to improve symptoms, quality of life, left ventricular ejection fraction and prognosis in patients with cardiac failure.

METHODS

Thirty patients with ischemic or idiopathic dilated cardiomyopathy and chronic left ventricular dysfunction (ejection fraction 26 +/- 6%) were randomized to a double-blind crossover trial of oral coenzyme Q versus placebo, each for 3 months. Right heart pressures, cardiac output and echocardiographic left ventricular volumes were measured at baseline and after each treatment phase, and quality of life was assessed using the Minnesota "Living With Heart Failure" questionnaire. It was calculated that to demonstrate an increase in left ventricular ejection fraction from 25% to 30% with a standard deviation of 5% using 95% confidence intervals with a power of 80% we would require 17 patients.

RESULTS

Twenty-seven completed both treatment phases. There was no significant difference in left ventricular ejection fraction, cardiac volumes or hemodynamic and quality of life indices after treatment with coenzyme Q or placebo, although plasma coenzyme Q levels increased from 903 +/- 345 nmol/l(-1) to 2,029 +/- 856 nmol/l(-1).

CONCLUSIONS

In patients with left ventricular dysfunction, treatment for three months with oral coenzyme Q failed to improve resting left ventricular systolic function or quality of life despite an increase in plasma levels of coenzyme Q to more than twice basal values.

Percutaneous transluminal coronary angioplasty in a 30-month-old child with embolic long segment occlusion of the left anterior descending artery

A 30-mo-old girl developed occlusion of her left anterior descending coronary artery following mitral valve replacement. She presented with refractory angina pectoris. Successful percutaneous transluminal coronary angioplasty of the left anterior descending artery was performed, resulting in restoration of flow, resolution of anginal symptoms, and early improvement in left ventricular function.

Angiographic follow-up and clinical experience with the flexible Tantalum Cordis stent

The Cordis stent is a flexible, highly radioopaque intracoronary stent engineered from a single Tantalum filament folded into a sinusoidal helical coil. It is premounted on a semicompliant balloon expandable stent delivery system. From September 1995-March 1996, 147 Cordis stents were deployed in 105 patients (aged 58+/-12 yr, 71% male). Clinical indications for stenting were unstable angina in 59 (55%), stable angina in 41 (38%), and acute myocardial infarction in 7 (7%). The target vessel was the right coronary artery in 45%, the left anterior descending in 31%, and the circumflex artery in 22%. One stent was deployed in a vein graft, and one stent was deployed in a left internal mammary artery graft. Stent deployment was achieved in all but one patient. Acute in-stent thrombosis occurred in 3 patients (2.9%). Two of these patients required urgent coronary artery bypass surgery. Subacute stent thrombosis occurred in 2 patients (1.9%). Minimum lumen diameter increased from 0.70+/-0.41 mm to 3.50+/-0.60 mm following stent placement. All patients received aspirin. Eighty-one patients (77%) received ticlopidine, and 4 patients (4%) received warfarin therapy. The mean hospital stay was 3.4+/-2.3 days. Six-month follow-up angiography was performed on 50 out of 55 eligible patients at one of the two institutions involved in this study. Computer-assisted quantitative coronary angiography defined a restenosis rate of 26%. Repeat revascularization was required in 8 patients (14.5%) at 6-mo follow-up. The Tantalum Cordis intracoronary stent is an effective and safe means of treating coronary lesions, even in patients with unstable ischemic syndromes. Acute and subacute rates of in-stent thrombosis were acceptable, and the long-term angiographic restenosis rates and need for repeat revascularization were favorable.

Thrombosis of a mechanical tricuspid valve prosthesis and of the left subclavian vein: successful therapy with thrombolysis

A patient with thrombosis of a mechanical prosthetic valve in the tricuspid position, simultaneous extensive left subclavian vein thrombotic occlusion, and pulmonary embolism is successfully treated with a urokinase infusion delivered using catheter-based techniques.

Multiple stent implantation in single coronary arteries: acute results and six-month angiographic follow-up

A total of 147 stents were implanted (in overlapping manner in 76% of vessels) in a single coronary artery in 59 patients (60 vessels, 97 lesions, 2.45 stents/vessel) over a period of 18 mo using high pressure stent deployment without ultrasound guidance. The indications for stenting were suboptimal percutaneous transluminal coronary angioplasty (PTCA) result (45%), primary prevention of restenosis (44%), acute closure (10%), and restenosis after plain balloon angioplasty (1%). One patient required emergency coronary artery bypass grafting (CABG) (extensive dissection), and one required early intervention with plain balloon angioplasty and intracoronary urokinase for stent thrombosis. There were no deaths. Thirteen patients had recurrence of angina within 6 mo and angiograms were performed in all. These showed intrastent restenosis in nine (all had successful repeat plain balloon angioplasty), development of new disease in other vessels along with restenosis close to the stent in the target vessel in one (underwent elective CABG) and normal angiograms with widely patent stents in three. Forty-five patients (77%) remained free of recurrent angina and 25 of these had follow-up angiograms (56%) at a mean of 172 days, two showing restenosis. Thus, the restenosis rate per patient in the symptomatic group (angiographic follow-up in 100%) was 77% and in the asymptomatic group (angiographic follow-up in 56%) was 8%. The restenosis rate in the subgroup with bailout stenting (n = 6) was 20% (angiographic follow-up in 83%). The overall restenosis rate per patient was 32% (overall angiographic follow-up in 66%). During the 6-mo follow-up period, one patient underwent elective CABG (1.7%), one sustained a non-Q myocardial infarction (1.7%), nine had repeat PTCA to the target vessel (15.5%), and there were no deaths. The event-free survival rate was 77%. Multiple stent implantation aided by high pressure stent deployment without ultrasound guidance and with adjunctive optimal antiplatelet therapy without oral anticoagulation seems to be a useful and effective revascularisation strategy to deal with long lesions and acute dissections with a high procedural success rate. The restenosis rate is acceptable and is not appreciably high as reported in previous studies from the "warfarin era."

Improving the results of coronary angioplasty

Coronary angioplasty has changed dramatically in the past three years with major reductions in suboptimal results and restenosis rates, and improvements in safety, efficacy and cost-effectiveness. Intracoronary stent implantation with optimisation of strut expansion and the abandonment of anticoagulants after deployment, have led to less entry-site complications, facilitated early hospital discharge, virtually abolished subacute stent thrombosis and resulted in a 50% reduction in target vessel revascularisation. Adjuvant medical treatment with anti-platelet agents, including glycoprotein IIb/IIIa receptor inhibitors, improves the safety of angioplasty and may further reduce the restenosis rate. Selective use of debulking devices has extended the indications for angioplasty. High resolution fluoroscopy, quantitative coronary angiography and intracoronary ultrasound leading to improved diagnosis, equipment selection and treatment have contributed to better outcomes. Further clinical trials will compare angioplasty and stent implantation with coronary bypass surgery in patients with multivessel coronary disease, and may extend the indications for percutaneous transluminal coronary angioplasty (PTCA) to selected patients with three vessel disease.

Growth factors released into the coronary circulation after vascular injury promote proliferation of human vascular smooth muscle cells in culture

OBJECTIVES

This study sought to 1) assess in vivo release of platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) into the coronary circulation after vascular injury in human subjects; and 2) evaluate mitogenic effects of PDGF and bFGF on the patient's own vascular smooth muscle cells (VSMCs).

BACKGROUND

Circumstantial evidence suggests involvement of PDGF and bFGF peptides in the neointimal response to vascular injury. To date, no study has shown biologically active growth factors within the coronary circulation after vascular injury in human subjects.

METHODS

In 18 patients, plasma PDGF AB, platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG) levels were measured in coronary sinus blood obtained before and up to 30 min after angioplasty. In five patients undergoing atherectomy, coronary sinus serum was added to cultured VSMCs derived from atherectomy tissue to assess the mitogenic potential of the serum. Mitogenicity attributable to PDGF and bFGF was determined using neutralizing antibodies to these factors. PDGF A, PDGF B and bFGF were localized within the atherectomy tissue using immunocytochemical analysis.

RESULTS

Before angioplasty, PDGF AB, PF4 and beta-TG levels were elevated threefold in patients scheduled for angioplasty compared with those in control patients (p < 0.01). Within 5 min of angioplasty, PDGF AB levels increased twofold and returned toward preangioplasty levels at 30 min; PF4 and beta-TG levels remained elevated. Serum obtained at 30 min after atherectomy showed a sixfold increase in mitogenicity compared with preatherectomy serum (p = 0.01). This increase in mitogenicity was reduced by 20%, 40% and 65% in the presence of neutralizing antibodies to PDGF, bFGF and PDGF + bFGF, respectively. PDGF A, PDGF B and bFGF were visualized within the intima of the atherectomy tissue.

CONCLUSIONS

The change in plasma PDGF level is consistent with first-phase release of PDGF after vascular injury. The increase in mitogenicity of serum suggests that PDGF and bFGF are biologically active.

Internal mammary vein to coronary artery anastomotic fistula

Two patients are presented where internal mammary artery grafting was performed for the relief of symptomatic coronary artery disease. At follow-up the internal mammary artery was occluded and a communication between the internal mammary vein and the native coronary artery was demonstrated. These patients were characterised by the early recurrence of angina or the appearance of a continuous murmur. Both patients were treated by re-operation with ligation of the arterio-venous fistula and saphenous vein grafting.

Elective implantation of intracoronary stents without intravascular ultrasound guidance or subsequent warfarin

Two hundred forty-three stents (203 Palmaz-Schatz, 40 Glanturco-Roubin) were electively Implanted in 188 lesions in 168 patients (mean age 58 +/- 10 years, 77% males) using angiographic but not ultrasound guidance. Patients were treated subsequently with aspirin and observed in hospital for up to 7 days. Those with acute myocardial infarction, radiolucent defects in coronary arteries suggestive of thrombus, and results that were not optimal after stent implantation were anticoagulated with warfarin and not Included in the study. Two had subacute stent thrombosis and two patients non-Q-wave myocardial infarction in-hospital. At follow-up (median 149 days) none had had subacute stent thrombosis, one suffered non-Q-wave myocardial infarction, none had died, and none had developed major complications at the vascular access site. Fourteen (8%) had undergone further revascularisation procedures. This initial experience suggests that aspirin is sufficient to prevent subacute stent thrombosis after elective high pressure assisted coronary stent implantation without intravascular ultrasound guidance if the angiographic appearance after stent deployment is optimal.

Thrombolytic treatment and proteinuria

OBJECTIVES

To determine whether patients with acute myocardial infarction undergoing thrombolysis with streptokinase develop changes in renal function.

DESIGN

Prospective assessment of renal function in 60 consecutive patients admitted with acute myocardial infarction.

SETTING

Tertiary referral centre and city general hospital.

PATIENTS

60 consecutive patients with acute myocardial infarction. Thirty eight were given streptokinase and 17 tissue plasminogen activator (alteplase) and five no thrombolytic agent (non-streptokinase group).

MAIN OUTCOME MEASURES

Proteinuria and creatinine clearance on admission (day 1) and on days 3 and 6; serum urea and creatinine concentrations on days 1 and 7; streptokinase IgG on days 1, 2, and 7.

RESULTS

Significant proteinuria (> 0.15 g/24 h) was found in 31 (82%) of the 38 patients in the streptokinase group (mean 0.47 g/24 h (95% confidence interval 0.35 to 0.6 g/24 h)) in the 24 hours after admission compared with six (27%) out of 22 in the non-streptokinase group (mean 0.17 g/24 h (0.12 to 0.2 g/24 h); P = 0.008). In the streptokinase group this decreased to the normal range by day 3 (mean 0.15 g/24 h (0.1 to 0.22 g/24 h); P = 0.0001 v baseline). Electrophoresis of urine showed the proteinuria to be glomerular in origin. Creatinine clearance and serum creatinine and urea concentrations were similar in both groups. In the streptokinase group detectable streptokinase IgG titres were found in 28 out of 32 (87%) patients. The median titre on admission was 16 (range 0-110); it fell to 3 (range 0-80; P = 0.001) by day 2 and increased to 61 (range 0-7700; P = 0.0002 v baseline) by day 7.

CONCLUSIONS

Streptokinase was associated with significant early onset proteinuria of glomerular origin. This started to resolve by day 3 and resulted in no deterioration in overall renal function. The temporal relation to the initial fall in antibody titre suggests that it could be the result of immune complex deposition in the glomeruli.

Effects of atrial natriuretic peptide on left ventricular function in hypertension

Atrial natriuretic peptide (ANP) has natriuretic and vasodilator actions that lower arterial pressure and may be beneficial to hypertensive patients. To assess the effects of ANP on left ventricular function in patients with hypertension, we compared it with the pure vasodilator nitroprusside. Simultaneous left ventricular micromanometer pressure and radionuclide volume were obtained at baseline, during nitroprusside infusion, during a second baseline period, and during ANP infusion in 10 patients with hypertension. Mean arterial pressure fell during ANP and nitroprusside. Heart rate and plasma norepinephrine levels increased by similar amounts during the two agents, whereas cardiac index and stroke volume index were unchanged during both. Peak positive left ventricular dP/dt fell similarly during ANP and nitroprusside, but left ventricular dP/dt at a developed pressure of 40 mm Hg, a less load-dependent index of contractility, was unchanged during both. The relation between end-systolic pressure and volume during ANP infusion was not shifted leftward or rightward from that during nitroprusside infusion, indicating no inotropic effect. Both ANP and nitroprusside shortened at time constant of isovolumic relaxation calculated by the logarithmic method but did not change the time constant calculated by the derivative method. Peak filling rate was unchanged from baseline during both agents. ANP did not shift the end-diastolic pressure-volume point away from the relation constructed from baseline and nitroprusside points. We conclude that ANP has no direct effect on myocardial contractile or diastolic function in patients with hypertension.

Percutaneous transluminal coronary angioplasty: clinical and quality of life outcomes one year later

BACKGROUND

The quality of life status of patients prior to and following percutaneous transluminal coronary angioplasty (PTCA) has not been comprehensively investigated.

AIM

This study was carried out to determine the effect that PTCA has on patients' quality of life.

METHODS

Data on 209 patients were collected one day pre-PTCA and at a mean of two and 11 months post-PTCA. Data on symptomatic status, functional capacity, life satisfaction and psychological well-being were analysed quantitatively. Clinical outcomes, patient perception of PTCA and employment status wee analysed by descriptive statistics.

RESULTS

Highly significant improvement in all quality of life measures was found at the early follow-up (p < .001). This improvement was sustained at the late follow-up. At the late follow-up, 58% of patients felt that PTCA had been very beneficial to their health and well-being, and 79% of workers had returned to work. PTCA was primarily successful in 91% of vessels dilated. There were no procedural-related deaths, 12 patients (6%) developed acute occlusion and three patients (1.5%) experienced myocardial infarction (MI). A symptomatic restenosis rate of 16% was found, including 19 patients (9%) requiring repeat PTCA and 14 (7%) undergoing coronary artery bypass grafting (CABG).

CONCLUSION

These findings suggest that, after PTCA, the majority of patients experienced improved quality of life which was sustained one year later.

Clinical results and quality of life after percutaneous transluminal coronary angioplasty: a preliminary report

To evaluate the effect of percutaneous transluminal coronary angioplasty (PTCA) on quality of life, data on symptomatic status, functional capacity, life satisfaction, and psychological wellness were collected on 102 patients at 1 day pre-PTCA and 2 months post-PTCA, and on the first 50 of these patients at 10 months post-PTCA. There were highly significant changes (p < 0.001) in all quality of life measures between pre-PTCA and the 1st follow-up measurements. No further significant changes occurred in these measures between the 1st and 2nd follow-up measurements, indicating that the initial improvement in quality of life was sustained over this period. Data on primary success rate, complications, and pre- and post-PTCA risk factor scores are also reported.

Effects of atrial natriuretic peptide on myocardial contractile and diastolic function in patients with heart failure

Atrial natriuretic peptide alters left ventricular performance in patients with heart failure. To assess the direct effects of this hormone on myocardial function, its actions were compared with those of the pure vasodilator nitroprusside in 10 patients with heart failure. Simultaneous left ventricular micromanometer pressure and radionuclide volume were obtained during a baseline period, during nitroprusside infusion, during a second baseline period and during atrial natriuretic peptide infusion. The baseline end-systolic pressure-volume relation was generated in nine patients from pressure-volume loops obtained during the two baseline periods and during afterload reduction with nitroprusside. Mean arterial pressure decreased with atrial natriuretic peptide (89 +/- 3 to 80 +/- 2 mm Hg, p less than 0.05) and by a greater amount with nitroprusside (90 +/- 4 to 73 +/- 3 mm Hg, p less than 0.05). Left ventricular end-diastolic pressure also decreased with atrial natriuretic peptide (24 +/- 2 to 16 +/- 3 mm Hg, p less than 0.05) and by a greater amount with nitroprusside (24 +/- 2 to 13 +/- 3 mm Hg, p less than 0.05). Cardiac index increased during infusion of each agent from 2.0 +/- 0.2 to 2.4 +/- 0.2 liters/min per m2 (p less than 0.01). Heart rate increased slightly with nitroprusside but did not change with atrial natriuretic peptide. Peak positive first derivative of left ventricular pressure (dP/dt), ejection fraction and stroke work index were unchanged by either agent. The relation between end-systolic pressure and volume during atrial natriuretic peptide infusion was shifted slightly leftward from the baseline value in four patients, slightly rightward in four and not at all in one patient, indicating no consistent inotropic effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular diastolic function in patients with left ventricular systolic dysfunction due to coronary artery disease and effect of nicardipine

To assess the effect of nicardipine on left ventricular (LV) diastolic function independent of concurrent effects on loading conditions in patients with LV systolic dysfunction due to coronary artery disease, equihypotensive doses of intravenous nitroprusside and nicardipine were administered to 12 patients with congestive heart failure due to previous myocardial infarction (LV ejection fraction less than 0.40). LV micromanometer pressure and simultaneous radionuclide volume were obtained during a baseline period, during nitroprusside infusion, during a second baseline period and during nicardipine infusion. Mean systemic arterial pressure decreased an average of 21 mm Hg with nitroprusside and 19 mm Hg with nicardipine. A greater decrease in LV end-diastolic pressure was observed with nitroprusside (29 +/- 2 to 15 +/- 2 mm Hg, p less than 0.01) than with nicardipine (29 +/- 2 to 25 +/- 3 mm Hg, p less than 0.05). There was a decrease in the time constant of relaxation during nitroprusside but not during nicardipine infusion. There was enough overlap in LV volumes in the baseline and nitroprusside periods to compare diastolic pressure-volume relations over a common range of volumes in 4 patients, and enough overlap in the baseline and nicardipine periods in 11 patients. The relation was shifted downward in 3 of 4 patients taking nitroprusside and in 6 of 11 patients taking nicardipine. The relation between end-diastolic pressure and volume was not shifted with nicardipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Techniques for assessing inotropic effects of drugs in patients with heart failure: application to the evaluation of nicardipine

Evaluation of new drugs for the treatment of patients with heart failure requires assessment of the inotropic effects of these agents. Use of traditional indexes of contractility has been limited by the confounding effects of load on these measures of contractile function, although they have yielded meaningful conclusions in some studies. Recently, the end-systolic pressure volume relation (ESPVR) has emerged as a relatively load-independent measure of contractility. Because it is difficult to construct the relation in the clinical setting, several approximations have been introduced, some of which have significant limitations. We have applied the ESPVR to the assessment of the inotropic effect of the new dihydropyridine calcium channel blocker, nicardipine, in 15 patients with heart failure caused by systolic dysfunction. We constructed left ventricular pressure-volume loops from micromanometer pressure and radionuclide volume and manipulated afterload with nitroprusside. In response to intravenous nicardipine, mean arterial pressure fell from 91 +/- 4 (mean +/- SEM) to 72 +/- 2 mm Hg, left ventricular end-diastolic pressure fell from 27 +/- 2 to 23 +/- 3 mm Hg, cardiac index increased from 1.7 +/- 0.1 to 2.4 +/- 0.1 L/min/m2, and left ventricular ejection fraction increased from 0.15 +/- 0.01 to 0.19 +/- 0.01 (all p less than 0.05). Heart rate did not change. A rightward shift of the ESPVR, indicating a negative inotropic effect of nicardipine, was observed in 12 of 14 patients (p less than 0.05). We conclude that nicardipine improves left ventricular pump performance despite its negative inotropic effect in patients with severe heart failure. The improvement in pump performance can be attributed to afterload reduction.

Inotropic effect of nicardipine in patients with heart failure: assessment by left ventricular end-systolic pressure-volume analysis

Nicardipine, a new dihydropyridine calcium channel blocker, has been investigated for the treatment of coronary artery disease and heart failure. To assess the inotropic effect of nicardipine in humans independent of its vasodilator effect, equihypotensive doses of intravenous nitroprusside (mean infusion rate 65 +/- 13 micrograms/min) and nicardipine (mean dose 5.2 +/- 0.4 mg) were administered to 15 patients with heart failure (New York Heart Association functional classes II to IV, radionuclide left ventricular ejection fraction 0.15 +/- 0.02). Left ventricular micromanometer pressure and simultaneous radionuclide left ventricular volume were obtained at baseline, during nitroprusside infusion, during a second baseline period and during nicardipine infusion. Heart rate did not change significantly with either nitroprusside or nicardipine. Mean systemic arterial pressure decreased by an average of 21 mm Hg with both drugs. A greater decrease in left ventricular end-diastolic pressure occurred with nitroprusside (27 +/- 2 to 14 +/- 2 mm Hg, p less than 0.01) than with nicardipine (27 +/- 2 to 23 +/- 3 mm Hg, p less than 0.05), and pulmonary capillary wedge pressure decreased significantly only with nitroprusside. Cardiac index increased from 1.8 +/- 0.1 to 2.1 +/- 0.1 liters/min per m2 (p less than 0.05) with nitroprusside and to a greater extent from 1.7 +/- 0.1 to 2.4 +/- 0.1 liters/min per m2 (p less than 0.01) with nicardipine. Left ventricular ejection fraction increased with nicardipine (0.15 +/- 0.01 to 0.19 +/- 0.01, p less than 0.01), but not with nitroprusside. Peak positive first derivative of left ventricular pressure (dP/dt) decreased by 9% with both agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Linearity of the left ventricular end-systolic pressure-volume relation in patients with severe heart failure

The left ventricular end-systolic pressure-volume relation is a relatively load-independent measure of left ventricular contractile function. Linearity of the relation derived from full left ventricular pressure-volume loops has not previously been demonstrated for patients with severe heart failure. Therefore, nine patients with markedly depressed left ventricular systolic function (ejection fraction 0.14 +/- 0.08) were studied with micromanometer left ventricular pressure measurement and simultaneous radionuclide ventriculography. Afterload was reduced with graded infusions of nitroprusside, allowing construction of pressure-volume loops under four afterload conditions in four patients and three afterload conditions in the other five patients. The end-systolic pressure-volume relation derived from the pressure-volume loops was found to be linear for the range of pressures and volumes examined, with correlation coefficients in individual patients ranging from 0.936 to 0.999 (mean 0.981). The mean slope of the relation (or end-systolic elastance) was 0.71 mm Hg/ml (range 0.42 to 1.52), and the extrapolated volume intercept at zero pressure was positive in all patients. An exponential relation between end-systolic elastance and ejection fraction was demonstrated for this group of patients. Approximations of end-systolic elastance obtained from measurements other than the full pressure-volume loops correlated variably with "true" elastance obtained from the pressure-volume loops. The relation between stroke work and end-diastolic volume was nonlinear in most patients. Thus, the end-systolic pressure-volume relation is linear in the "physiologic" range in patients with severe heart failure. This finding should permit construction of the relation from two loading conditions in clinical studies, facilitating its use as an index of contractile function in patients with heart failure.

Differentiation of restrictive cardiomyopathy from pericardial constriction: assessment of diastolic function by radionuclide angiography

Diastolic filling variables were studied in 12 patients with the hemodynamic features of constriction, of whom 5 had restrictive cardiomyopathy, 5 had pericardial constriction and 2 had combined pericardial constriction and restrictive cardiomyopathy. The values were compared with those in 10 normal subjects of comparable age. The filling fractions between 10% and 70% of the diastolic time interval were greater in patients with pericardial constriction than in those with restrictive cardiomyopathy (p less than 0.01 between 20% and 50%, p less than 0.05 at 10%, 60% and 70%), with no overlap. The filling fractions in patients with pericardial constriction were also greater than those in normal subjects between 10% and 60% of the diastolic time interval. The filling fraction was lower in patients with restrictive cardiomyopathy than in normal subjects at 40% of the diastolic time interval (p less than 0.05). The time to peak filling rate in patients with pericardial constriction was shorter (110 +/- 14 ms) than in those with restrictive cardiomyopathy (195 +/- 45 ms, p less than 0.01) or in normal subjects (173 +/- 32 ms, p less than 0.01). The percent of atrial contribution to left ventricular filling was higher in those with restrictive cardiomyopathy (45 +/- 17%) than in those with pericardial constriction (21 +/- 6%, p less than 0.05) or in normal subjects (24 +/- 9%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic features of a mediastinal pancreatic pseudocyst

Cross sectional echocardiography detected a mediastinal pancreatic pseudocyst which caused extracardiac compression in a 49 year old man. Computed tomography confirmed the presence of a cystic lesion lying behind the heart and extending from the pancreas to above the carina. Surgical decompression resulted in resolution of the clinical and echocardiographic findings.