Effect of low dose intracoronary alteplase on global circumferential strain (myocardial strain CMR substudy from the T-TIME trial)

Background

Microvascular obstruction affects half of patients with ST-segment elevation myocardial infarction (STEMI) and confers an adverse prognosis. Feature-tracking (FT) cardiac magnetic resonance (CMR) allows myocardial strain assessment from standard cine images without the need for specialist sequences. Myocardial strain reflects both systolic and diastolic function allowing the assessment of both global and regional myocardial deformation. Strain recovery is impaired in patients with microvascular obstruction. There is growing evidence to suggest that global circumferential strain may offer incremental value beyond traditional CMR endpoints.

Purpose

We aimed to determine whether a therapeutic strategy involving low-dose intracoronary alteplase improves global circumferential strain in STEMI.

Methods

Between March 17, 2016, and December 21, 2017, 440 patients presenting at 11 hospitals in the United Kingdom within 6 hours of STEMI were randomised in a 1:1:1 dose-ranging trial design. Participants were randomly assigned to treatment with placebo (n=151), alteplase 10mg (n=144), or alteplase 20mg (n=145). The primary outcome was the amount of microvascular obstruction (%left ventricular mass) quantified by CMR at 2–7 days. Global circumferential strain was a prespecified secondary endpoint measured at 2–7 days and 3 months. Troponin T AUC was measured at 0, 2, and 24 hours post reperfusion. Patients were followed up to 1 year with all events adjudicated by an independent committee.

Results

Among the 440 patients who were randomised (mean age 60.5 years; 85% male), the primary endpoint was achieved in 396 (90%), all patients were followed up to 1 year for clinical events. The amount (mean, standard deviation) of microvascular obstruction was not different between the groups (2.3% vs. 2.6% vs. 3.5% left ventricular mass); p=0.28. Global circumferential strain was worse in patients receiving alteplase. −23.1% (placebo) vs −20.6 (10mg alteplase) vs −22.0% (20mg alteplase); mean difference for both doses combined vs placebo: 1.8% (95% CI 0.5, 3.2), p=0.009. There were no differences between groups in the other CMR endpoints including LV ejection fraction (LVEF). The area-under-the-curve for troponin T measured in 317 (72%) patients was increased in both treatment groups compared to placebo, mean difference 1.53 (95% CI: 1.16, 2.01), p=0.002. There were no differences in MACE at 1 year; placebo n=16 (10.6%), 10mg alteplase n=22 (15.3%), 20mg alteplase group n=15 (10.3%).

Conclusion

In patients presenting within 6 hours of STEMI, low-dose intracoronary alteplase compared with placebo did not reduce microvascular obstruction. There was a reduction in global circumferential strain and an increase in Troponin T AUC supporting an increase in myocardial injury early after reperfusion in patients receiving alteplase. There was no differences in MACE at one year suggesting no long-term clinical sequelae.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): T-TIME was supported by grant 12/170/4 from the Efficacy and Mechanism Evaluation (EME) programme of the National Institute for Health Research (NIHR-EME). Boehringer-Ingelheim U.K. Ltd. provided the study drugs (alteplase 10mg, 20mg), matched placebo, and sterile water for injection. Study recruitment flowchartTable- Study endpoints

Angina, quality of life and prognosis: prospective comparison of patients undergoing invasive management

Background

Angina is associated with impaired quality of life and an adverse prognosis.

Purpose

Prospectively evaluate quality of life and clinical outcomes in patients with angina undergoing invasive coronary angiography according to endotype: symptoms and/or signs of ischaemia and no obstructive coronary artery disease (INOCA) compared to obstructive coronary artery disease subjects managed by medical therapy, revascularization with percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery, respectively.

Methods

We conducted a prospective clinical evaluation of patients with angina undergoing clinically indicated invasive management (NCT03193294). Symptom severity and quality of life were assessed at baseline and repeated after 6 months. Comparisons between treatment groups were based on analysis of covariance general linear models adjusting for baseline score, sex, and cardiovascular risk. INOCA subjects were considered as one diagnostic group and not all subjects had invasive vasoreactivity testing.

Results

391 patients (mean age 62±10 years, 52% female) were enrolled over 12 months and classified into one of four groups: INOCA (N=185; 47%), obstructive CAD treated by PCI (N=126; 32%), obstructive CAD treated by CABG (N=48; 12%) and obstructive CAD managed with medical therapy (N=32; 8%). After adjusting for between group differences and overall risk, INOCA subjects had worse angina and worse treatment response at follow up (21% and 27% reduction in angina score compared to CAD patients revascularized with PCI and CABG respectively). INOCA subjects had numerically lower treatment response than CAD patients managed with medications (6.4 units, −12%; P=0.181). Population baseline mean Seattle Angina Questionnaire (SAQ) frequency score (60±26) and SAQ summary score (52.5±19) were similar between groups. The absolute difference was 6.4 units versus medically managed CAD (95% CI: −3.0 to 15.9; P=0.181), 11.3 units versus the CAD group undergoing PCI (6.1 to 16.5; P<0.001) and 14.3 units versus CABG (6.2 to 22.3; P=0.001). INOCA subjects had overall reduced quality of life (EQ5D index) and increased psychological distress scores versus all CAD groups at 6 months. During longer-term follow-up (median 18 months), 23 (6%) MACE events occurred with no differences between the groups (Kaplan Meier log-rank P=0.890).

Conclusion(s)

Patients with INOCA had more severe angina symptoms reflecting worse quality of life and treatment response at 6 months with similar MACE as CAD subjects even after adjustment for confounding factors. This study highlights the need for evidence-based antianginal therapies and disease-modifying treatments for angina patients regardless of the presence of obstructive coronary disease.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): This work was funded by the British Heart Foundation (PG/17/2532884; RE/13/5/30177; RE/18/6134217)

P2707Invasive coronary physiology during primary percutaneous coronary intervention in patients treated with intracoronary alteplase or placebo: the double-blind T-TIME physiology substudy

Background

Impaired microcirculatory reperfusion worsens prognosis post-primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). Intracoronary (IC) alteplase targets persisting thrombus post-reperfusion & distal embolisation. In the T-TIME trial microvascular obstruction on cardiac magnetic resonance (CMR) did not differ with IC alteplase vs placebo.

Purpose

To prospectively determine if index of microcirculatory resistance (IMR) is lower & coronary flow reserve (CFR) or resistive reserve ratio (RRR) are higher (improved) with IC alteplase, & to provide mechanistic insights.

Methods

A pre-planned substudy of the main protocol. From 2016–2017, STEMI patients from 3 UK hospitals ≤6 hrs ischaemic time were randomised in a 1:1:1 dose-ranging, double-blind design. Following standard care reperfusion, alteplase (10 or 20mg) or placebo was infused over 5–10 mins proximal to the culprit lesion pre-stenting. IMR (primary outcome), CFR & RRR (secondary outcomes) were measured in the culprit artery post-PCI. Physiology results were obscured from clinicians acquiring the data, to maintain blinding. CMR was performed 2 days & 3 months post-STEMI. Subgroup analyses were prespecified including by ischaemic time (<2 hours, 2–4 hrs, >4 hrs) & IMR threshold >32.

Results

In 144 patients (mean age 59 yrs, 80% male), IMR, CFR or RRR post-PCI did not differ with alteplase vs placebo (Table). Patients with ischaemic time <2 hrs had a dose related increase in CFR (placebo 1.2 [IQR 1.1–1.7], alteplase 10mg 1.4 [IQR 1.0–1.8], alteplase 20mg 2.0 [IQR 1.8–2.3] p=0.01 for interaction) & RRR (placebo 1.5 [IQR 1.3–1.9], alteplase 10mg 1.6 [1.1–2.2], alteplase 20mg 2.2 [2.0–2.6], p=0.03 for interaction). In subjects with post-PCI IMR>32, % ST-resolution at 60 mins was worse with alteplase 10mg vs placebo (23.1±53.9 vs 50.9±31.5) & in those with IMR≤32% ST-resolution at 60 mins was better with alteplase 20mg vs placebo (68.0±30.7 vs 39.1±43.2), p=0.002 for interaction. The CMR findings in the substudy & overall trial populations were consistent.

Main results Placebo Alteplase 10mg Alteplase 20mg (n=53) (n=41) (n=50) IMR, median (IQR) 33.0 (17.0–57.0) 22.0 (17.0–42.0) 37.0 (20.0–57.8) p=0.15 p=0.78 CFR, median (IQR) 1.3 (1.1–1.8) 1.4 (1.1–1.9) 1.5 (1.1–2.0) p=0.92 p=0.74 RRR, median (IQR) 1.6 (1.3–2.2) 1.6 (1.4–2.6) 1.8 (1.3–2.4) p=0.69 p=0.81 P-values for comparison of alteplase with placebo.

Conclusions

In acute STEMI with ischaemic time ≤6 hrs, IMR, CFR or RRR post-PCI did not differ with alteplase vs placebo. In those with shorter ischaemic times (<2 hrs) CFR & RRR, but not IMR, were improved with alteplase. We observed interactions between alteplase dose, ischaemic time & mechanisms of effect.

Acknowledgement/Funding

Dr Maznyczka is funded by a fellowship from the British Heart Foundation (FS/16/74/32573). T-TIME was funded by grant 12/170/4 from NIHR-EME

6030Effects of adjunctive treatment with low-dose alteplase during primary percutaneous coronary intervention according to ischaemic time

Background

Microvascular obstruction affects half of patients with acute ST-segment elevation myocardial infarction and confers an adverse prognosis.

Purpose

We aimed to determine whether the efficacy and safety of a therapeutic strategy involving low-dose intra-coronary alteplase infused early after coronary reperfusion associates with ischaemic time.

Methods

We conducted a prospective, multicentre, parallel group, 1:1:1 randomised, dose-ranging trial in patients undergoing primary percutaneous coronary intervention. Ischaemic time, defined as the time from symptom onset to coronary reperfusion, was a pre-specified sub-group of interest. Between March 17, 2016, and December 21, 2017, 440 patients presenting at 11 hospitals in the UK were enrolled with follow up to 3 months. Patients with acute myocardial infarction due to occlusion of a major coronary artery presenting ≤6 hours from symptom onset were randomly assigned to treatment with placebo, alteplase 10mg or alteplase 20mg. The primary outcome was the amount of microvascular obstruction disclosed by cardiac magnetic resonance imaging at 2–7 days. Secondary outcomes included infarct size, myocardial haemorrhage, left ventricular ejection fraction, and troponin T area-under-the curve.

Results

440 patients were randomized (figure), the primary endpoint was achieved in 396 (90%), seventeen (3.9%) withdrew and all other patients were followed up to 3 months. In the primary analysis, the amount of microvascular obstruction did not differ between the groups. Their ischaemic times were: ≤2 hours, n=98; ≥2–<4 hours, n=215; and ≥4–6 hours, n=83.

In patients with an ischaemic time ≥4 hours, treatment with alteplase (10 mg, n=26; 20 mg, n=30) was associated with a dose dependent increase in the amount (mean) of microvascular obstruction (% left ventricular mass) compared to placebo (n=27) 1.14 vs. 3.11 vs. 5.20; mean difference on square root scale 0.81 (95% CI 0.21, 1.42), p=0.009. The interaction test between ischaemic time and treatment (active vs. placebo) was not statistically significant p=0.06, however when the interaction was assessed for a trend across treatment groups this did reach statistical significance, p=0.018.

Furthermore, a higher proportion of patients presenting ≥4–6 hours treated with 20 mg of alteplase had myocardial haemorrhage (59.3%) compared to the placebo group (28.0%), odds ratio 3.81 (95% CI 1.19, 12.25), p=0.025. The amount of haemorrhage was also greater; estimated mean difference 3.49 (95% CI 1.22, 5.75), p=0.0026. No between-treatment group differences for myocardial haemorrhage were observed in patients presenting with shorter ischaemic times.

Study flow diagram

Conclusions

In patients presenting with an ischaemic time ≥4 hours, adjunctive treatment with low-dose intra-coronary alteplase during primary PCI was associated with increases in microvascular obstruction and myocardial haemorrhage. The mechanism may involve haemorrhagic transformation within the infarct core.

Acknowledgement/Funding

NIHR EME programme (reference: 12/170/45); British Heart Foundation (BHF reference FS/16/74/32573)

Limited clinical utility of CT coronary angiography in a district hospital setting

BACKGROUND

Studies have demonstrated considerable accuracy of multi-slice CT coronary angiography (MSCT-CA) in comparison to invasive coronary angiography (I-CA) for evaluating coronary artery disease (CAD). The extent to which published MSCT-CA accuracy parameters are transferable to routine practice beyond high-volume tertiary centres is unknown.

AIM

To determine the accuracy of MSCT-CA for the detection of CAD in a Scottish district general hospital.

DESIGN

Prospective study of diagnostic accuracy.

METHOD

One hundred patients with suspected CAD recruited from two Glasgow hospitals underwent both MSCT-CA (Philips Brilliance 40 × 0.625 collimation, 50-200 ms temporal resolution) and I-CA. Studies were reported by independent, blinded radiologists and cardiologists and compared using the AHA 15-segment model.

RESULTS

Of 100 patients [55 male, 45 female, mean (SD) age 58.0 (10.7) years], 59 and 41% had low-intermediate and high pre-test probabilities of significant CAD, respectively. Mean (SD) heart rate during MSCT-CA was 68.8 (9.0) bpm. Fifty-seven per cent of patients had coronary artery calcification and 35% were obese. Patient prevalence of CAD was 38%. Per-patient sensitivity, specificity, positive and negative (NPV) predictive values for MSCT-CA were 92.1, 47.5, 52.2 and 90.6%, respectively. NPV was reduced to 75.0% in the high pre-test probability group. Specificity was compromised in patients with sub-optimally controlled heart rates, calcified arteries and elevated BMI.

CONCLUSION

Forty-Slice MSCT-CA has a high NPV for ruling out significant CAD when performed in a district hospital setting in patients with low-intermediate pre-test probability and minimal arterial calcification. Specificity is compromised by clinically appropriate strategies for dealing with unevaluable studies. Effective heart rate control during MSCT-CA is imperative. National guidelines should be utilized to govern patient selection and direct MSCT-CA reporter training to ensure quality control.

Unemployment and deprivation are associated with a poorer outcome following percutaneous coronary angioplasty

This prospective observational study aimed to assess the impact of employment status and deprivation on quality of life 12 months after percutaneous coronary intervention (PCI). Patients completed a questionnaire at baseline and at 1 year follow-up including a health utility score (EQ-5D), symptoms and employment status. Deprivation was assessed using the Carstairs' deprivation category based on area postcodes. The majority (79.6%) of patients of working age returned to work within 12 months. Unemployment was associated with a lower quality of life (QoL) at baseline (0.49 (0.32) vs 0.61 (0.27), p=0.002) and less improvement in QoL 1 year after PCI (0.15 (0.37) vs 0.26 (0.31), p<0.012). Furthermore, unemployed patients had significantly less improvement in chest pain score (p=0.002) and breathlessness (p<0.001). Unemployed patients from the most deprived areas had lowest QoL at follow-up and least improvement in QoL at 1 year. Unemployment and deprivation are associated with poorer outcomes following PCI.

Influence of socioeconomic status on clinical outcomes and quality of life after percutaneous coronary intervention

OBJECTIVES

To determine whether socioeconomic status (SES) influences clinical outcomes and quality of life after percutaneous coronary intervention (PCI).

DESIGN

Prospective observational study.

SETTING

Two interventional cardiac centres.

PARTICIPANTS

1346 consecutive patients undergoing PCI over a 12-month period.

OUTCOMES

Self reported health-related quality of life (HRQoL; EuroQol-5 Dimensions (EQ-5D); EuroQol Visual Analogue Scale (EQ-VAS)), repeat angiography, revascularisation, hospital admission, myocardial infarction and death within 12 months, by SES derived using postal address code.

MAIN RESULTS

No significant differences were found between patients with high and low SES in the occurrence of repeat angiography (p = 0.55), repeat revascularisation (PCI, p = 0.81, CAEG, p = 0.27), total cardiac hospitalisation (p = 0.10), myocardial infarction (p = 0.97) or death 12 months after PCI (p = 0.88). Non-procedure-related readmissions were higher in patients with low SES (18.6% v 13.7%; p = 0.025). After adjustment for confounding factors, patients with low SES had lower HRQoL scores at baseline (95% CI for difference 0.01 to 0.14; p = 0.003) and at 12 months (95% CI 0.07 to 0.17; p<0.001) compared with those with high SES.

CONCLUSIONS

Clinical outcomes were similar for patients in different SES groups. Patients with low SES had considerably more non-procedure-related readmissions and lower quality-of-life scores. Future studies on HRQoL after coronary revascularisation should take account of these important differences related to SES.

Abnormal haemoglobin levels in acute coronary syndromes

BACKGROUND

Anaemia is an adverse prognostic marker in acute coronary syndromes (ACS), but the epidemiology of abnormal haemoglobin levels in such patients is uncertain.

AIMS

To investigate the prevalence, nature and predictors of abnormal haemoglobin levels in ACS patients at admission.

DESIGN

Observational study.

METHODS

All emergency admissions from January to April 2005 were assessed within 24-48 h of hospital admission. ACS patients (unstable angina, non-ST-elevation or ST-elevation myocardial infarction) were enrolled (n = 320, 190 men). Clinical information was recorded.

RESULTS

Overall, 71% had unstable angina; 18% non-ST-elevation myocardial infarction (MI), and 11% ST-elevation MI. Mean +/- SD haemoglobin was 14.3 +/- 1.7 g/dl in men and 13.2 +/- 1.5 g/dl in women. Abnormal haemoglobin was more common in men (65, 34%) than in women (34, 22%) (p = 0.013). Anaemia (haemoglobin <13 g/dl in men, or <12.0 g/dl in women) was recorded in 35 (18%) men and 24 (18%) women. All had admission haemoglobin >8 g/dl, and anaemia was usually normocytic. Multivariate predictors of anaemia (OR, 95%CI) were age (1.07, 1.04-1.1) and serum albumin (0.90, 0.81-1.00). Elevated haemoglobin (>16 g/dl) was recorded in 30 (16%) men and 4 (3%) women (p < 0.01), and was more common in ST-elevation MI patients (26%) than in unstable angina or non-ST elevation MI patients (9%) (p = 0.005). In patients who underwent invasive management with a post-procedure haemoglobin the following day (n = 85), 15 (18%) new cases of anaemia were detected. Admission duration correlated with haemoglobin (p < 0.01), creatinine (p < 0.01), troponin I (p < 0.01) and C-reactive protein (p < 0.01). Anaemia was more common in those who died in hospital (3, 60%) than in those who survived (56, 18%) (adjusted p = 0.0135).

DISCUSSION

Abnormal haemoglobin levels were common in our ACS admissions. Anaemia was generally mild. Increasing age and interventional management were associated with anaemia, which in turn was associated with adverse in-hospital outcomes. Interventions to prevent and detect anaemia in this setting merit prospective testing.

Effects of changing clinical practice on costs and outcomes of percutaneous coronary intervention between 1998 and 2002

AIM

To assess the effect of changing clinical practice on the costs and outcomes of percutaneous coronary intervention (PCI) between 1998 and 2002.

SETTING

Two tertiary interventional centres.

PATIENTS

Consecutive patients undergoing PCI over a 12-month period between 1998 and 2002.

DESIGN

Comparative observational study of costs and 12-month clinical outcomes of consecutive PCI procedures in 1998 (n = 1047) and 2002 (n = 1346). Clinical data were recorded in the Scottish PCI register. Repeat PCI, coronary artery bypass graft and mortality were obtained by record linkage. Costs of equipment were calculated using a computerised bar-code system and standard National Health Service reference costs.

RESULTS

Between 1998 and 2002, the use of bare metal stents increased from 44% to 81%, and the use of glycoprotein IIB/IIIA inhibitors increased from 0% to 14% of cases. During this time, a significant reduction was observed in repeat target-vessel PCI (from 8.4% to 5.1%, p = 0.001), any repeat PCI (from 11.7% to 9.2%, p = 0.05) and any repeat revascularisation (from 15.1% to 11.3%, p = 0.009) within 12 months. Significantly higher cost per case in 2002 compared with 1998 (mean (standard deviation) 2311 pounds (1158) v 1785 pounds (907), p<0.001) was mainly due to increased contribution from bed-day costs in 2002 (45.0% (16.3%) v 26.2% (12.6%), p = 0.01) associated with non-elective cases spending significantly longer in hospital (6.22 (4.3) v 4.6 (4.3) days, p = 0.01).

CONCLUSIONS

Greater use of stents and glycoprotein IIb/IIIa inhibitors between 1998 and 2002 has been accompanied by a marked reduction in the need for repeat revascularisation. Longer duration of hospital stay for non-elective cases is mainly responsible for increasing costs. Strategies to reduce the length of stay could considerably reduce the costs of PCI.

Hospital volume of throughput and periprocedural and medium-term adverse events after percutaneous coronary intervention: retrospective cohort study of all 17,417 procedures undertaken in Scotland, 1997-2003

OBJECTIVE

To determine whether percutaneous coronary intervention (PCI) hospital volume of throughput is associated with periprocedural and medium-term events, and whether any associations are independent of differences in case mix.

DESIGN

Retrospective cohort study of all PCIs undertaken in Scottish National Health Service hospitals over a six-year period.

METHODS

All PCIs in Scotland during 1997-2003 were examined. Linkage to administrative databases identified events over two years' follow up. The risk of events by hospital volume at 30 days and two years was compared by using logistic regression and Cox proportional hazards models.

RESULTS

Of the 17,417 PCIs, 4900 (28%) were in low-volume hospitals and 3242 (19%) in high-volume hospitals. After adjustment for case mix, there were no significant differences in risk of death or myocardial infarction. Patients treated in high-volume hospitals were less likely to require emergency surgery (adjusted odds ratio 0.18, 95% confidence interval (CI) 0.07 to 0.54, p = 0.002). Over two years, patients in high-volume hospitals were less likely to undergo surgery (adjusted hazard ratio 0.52, 95% CI 0.35 to 0.75, p = 0.001), but this was offset by an increased likelihood of further PCI. There was no net difference in coronary revascularisation or in overall events.

CONCLUSION

Death and myocardial infarction were infrequent complications of PCI and did not differ significantly by volume. Emergency surgery was less common in high-volume hospitals. Over two years, patients treated in high-volume centres were as likely to undergo some form of revascularisation but less likely to undergo surgery.

Variations in clinical decision-making between cardiologists and cardiac surgeons; a case for management by multidisciplinary teams?

Objective

To assess variations in decisions to revascularise patients with coronary heart disease between general cardiologists, interventional cardiologists and cardiac surgeons

Design

Six cases of coronary heart disease were presented at an open meeting in a standard format including clinical details which might influence the decision to revascularise. Clinicians (n = 53) were then asked to vote using an anonymous electronic system for one of 5 treatment options: medical, surgical (CABG), percutaneous coronary intervention (PCI) or initially medical proceeding to revascularisation if symptoms dictated. Each case was then discussed in an open forum following which clinicians were asked to revote. Differences in treatment preference were compared by chi squared test and agreement between groups and between voting rounds compared using Kappa.

Results

Surgeons were more likely to choose surgery as a form of treatment (p = 0.034) while interventional cardiologists were more likely to choose PCI (p = 0.056). There were no significant differences between non-interventional and interventional cardiologists (p = 0.13) in their choice of treatment. There was poor agreement between all clinicians in the first round of voting (Kappa 0.26) but this improved to a moderate level of agreement after open discussion for the second vote (Kappa 0.44). The level of agreement among surgeons (0.15) was less than that for cardiologists (0.34) in Round 1, but was similar in Round 2 (0.45 and 0.45 respectively)

Conclusion

In this case series, there was poor agreement between cardiac clinical specialists in the choice of treatment offered to patients. Open discussion appeared to improve agreement. These results would support the need for decisions to revascularise to be made by a multidisciplinary panel.

Comparison of survival following coronary artery bypass grafting vs. percutaneous coronary intervention in diabetic and non-diabetic patients: retrospective cohort study of 6320 procedures

AIM

To determine whether mortality following percutaneous coronary intervention vs. coronary bypass grafting varies according to whether or not patients have diabetes.

METHODS

We used the Scottish Coronary Revascularization Register to identify all patients undergoing revascularization in Scottish NHS hospitals since 1997. We excluded single-vessel disease, left main stem stenosis, and bypass grafting performed at the same time as other operations. We used death certificate data from the Registrar General to identify all subsequent deaths.

RESULTS

Of the 6320 eligible procedures, 5042 (80%) were bypass grafts and 1278 (20%) angioplasties. Overall 831 (13%) patients had diabetes with no significant difference by procedure (13% vs. 12%). A total of 382 deaths occurred over a mean follow-up of 2.3 years. Diabetic patients had a poorer prognosis following both surgery (adjusted hazards ratio (HR) 1.43, 95% confidence interval (CI) 1.08, 1.89) and percutaneous intervention (adjusted HR 2.58, 95% CI 1.43, 4.63). Among non-diabetic patients, no significant differences in mortality were detected between the two procedures. Among diabetic patients, no significant difference was detected in those with two-vessel disease. In those with impaired left ventricular function and triple-vessel disease, angioplasty was associated with a significantly higher risk of death (adjusted HR 3.58, 95% CI 1.40, 9.19).

CONCLUSIONS

This is the first study to demonstrate statistically significant results that support the BARI trial findings. Our study demonstrated a significant difference for triple-vessel disease but not two-vessel disease. The former may be due to incomplete revascularization using percutaneous intervention. Our results require corroboration from randomized trials.

Comparing performance between coronary intervention centres requires detailed case-mix adjusted analysis

This study compares 12 month clinical outcomes and procedural costs at two interventional centres with significant differences in crude mortality and revascularization outcomes between 1997 and 1998. Percutaneous coronary intervention (PCI) registry data on 1046 consecutive patients treated contemporaneously at two university centres were linked to hospital discharge and death data to provide 12 month follow-up information on survival and repeat revascularization. Costs were determined by detailed analysis of equipment use, length of stay and staff from 100 contemporary cases at each centre to derive a procedural cost model. This model was then applied retrospectively to estimate cost per procedure. Stents were used more frequently at one centre (56 versus 26 per cent, chi(2) test, p < 0.001) resulting in greater procedural cost [mean (SE), pounds sterling 1970 (34) versus pounds sterling 1521 (39), t-test, p < 0.001). One year repeat target vessel PCI was significantly greater at the centre using more stents (10.3 versus 5.6 per cent, chi(2) test, p = 0.005) and the need for any repeat revascularization (PCI or coronary artery by-pass surgery) was also significantly greater at this centre (18.4 versus 10.8 per cent, chi(2) test, p < 0.001). Cox regression revealed that after correction for case-mix the difference in the need for repeat target vessel PCI between the two centres was no longer significant (p = 0.15). In the two centres studied, crude differences in cost per case, mortality and the need for revascularization were largely accounted for by significant differences in case-mix. Comparison of outcomes and costs between centres should not be published without careful adjustment for differences in case-mix.

Outcomes following coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in the stent era: a prospective study of all 9890 consecutive patients operated on in Scotland over a two year period

OBJECTIVE

To determine current outcomes of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG).

DESIGN

The Scottish coronary revascularisation register provided prospectively collected data on case mix and in-hospital complications for all revascularisation procedures between April 1997 and March 1999 (4775 PTCA; 5115 CABG). Linkage to routine hospital discharge and death data provided follow up information on survival and repeat revascularisation.

RESULTS

Stents were used in 51% of PTCA procedures. CABG patients were older, had more severe coronary disease, and had greater comorbidity. PTCA was more likely to be undertaken as an urgent or emergency procedure. Perioperative death and urgent surgery followed 0.3% and 0.6% of PTCA procedures, respectively. Case fatality rates were higher following CABG, with 6.7% dead within two years compared with 3.4% following PTCA. PTCA was more often followed by readmission for ischaemic heart disease, repeat angiography, or revascularisation: 22.8% of patients had repeat revascularisation within two years, compared with 1.8% following CABG.

CONCLUSIONS

The severity of coronary heart disease was greater than in previously published registry studies and randomised trials. Despite this, overall survival figures were comparable and repeat revascularisation rates lower, particularly following PTCA. Perioperative death and urgent surgery following PTCA were also lower. These favourable outcomes may be attributable, in part, to increased use of bail out and elective stenting.

Coronary venous lipid peroxide concentrations after coronary angioplasty: correlation with biochemical and electrocardiographic evidence of myocardial ischaemia

BACKGROUND

Raised lipid peroxide concentrations in coronary venous plasma have been reported after coronary angioplasty in humans. This may reflect increased free radical activity after myocardial ischaemia and reperfusion. If so, it may be possible to correlate lipid peroxide concentrations with the degree of myocardial ischaemia produced during angioplasty.

METHODS

15 patients (age range 42-70; 12 men) with stable angina pectoris undergoing angioplasty of a proximal left anterior descending coronary artery stenosis were studied. Plasma lipid peroxide and lactate concentrations were measured in sequential blood samples taken from the great cardiac vein before and immediately after one to five serial 60 second balloon inflations. The maximum ST segment shift during each balloon inflation was also measured.

RESULTS

Lipid peroxide concentrations in coronary venous plasma were raised from pre-angioplasty values by more than 2 SDs of the relevant measurement error after 27 out of 46 (59%) balloon inflations. Lactate concentrations were raised after 43 out of 46 (93%) balloon inflations. No significant difference was found between the peak percentage change of either lipid peroxide or lactate concentrations after any of the first three serial inflations. The maximum ST segment shift after each of the first three serial inflations was also similar. Coronary venous lactate concentrations after balloon inflation correlated positively with the maximum ST segment shift, but did not correlate with lipid peroxide concentrations.

CONCLUSIONS

Raised lipid peroxide concentrations in coronary venous plasma can be detected in humans after balloon angioplasty. There is no positive correlation between lipid peroxide concentrations in coronary venous plasma after angioplasty and the degree of preceding myocardial ischaemia as assessed by either ST segment shift or lactate production. These indices showed that one to three serial 60 second balloon inflations each produce a similar degree of myocardial ischaemia. The origin of the raised lipid peroxide concentrations in coronary venous plasma after angioplasty remains unknown.