Consensus guidelines for interventional cardiology services delivery during covid-19 pandemic in Australia and new Zealand.

The global coronavirus disease (COVID-19) pandemic poses an unprecedented stress on healthcare systems internationally. These Health system-wide demands call for efficient utilisation of resources at this time in a fair, consistent, ethical and efficient manner would improve our ability to treat patients. Excellent co-operation between hospital units (especially intensive care unit [ICU], emergency department [ED] and cardiology) is critical in ensuring optimal patient outcomes. The purpose of this document is to provide practical guidelines for the effective use of interventional cardiology services in Australia and New Zealand. The document will be updated regularly as new evidence and knowledge is gained with time. Goals Considerations.

Long-term outcomes in patients with restrictive filling following ST-segment elevation myocardial infarction.

This study evaluated the effect of restrictive filling pattern (RFP) on 5-year outcomes in patients following ST-segment elevation myocardial infarction (STEMI). A hundred STEMI patients treated either by rescue or primary percutaneous coronary intervention with an echocardiogram performed within 6 weeks of STEMI comprised the study group. Creatinine kinase (CK) and left ventricular ejection fraction were independent determinants of RFP, and RFP was an independent predictor of cardiac and all-cause mortality at median follow up of 5 years.

The pharmaco-invasive approach to STEMI: when should fibrinolytic-treated patients go to the "cath lab"?

Although primary percutaneous coronary intervention (PCI) in clinical trials has lower rates of reinfarction, stroke and mortality than fibrinolytic therapy, because of system delays in routine practice, field triage and prehospital administration of fibrinolytic therapy may lead to similar clinical outcomes, especially in those patients who present in the first 2 h after symptom onset. Necessary for these outcomes is the liberal use of both rescue PCI and in-hospital revascularisation. Non-invasive prediction of failed reperfusion may be enhanced by the use of ST recovery, patient characteristics and troponin T levels, measured by point-of-care assays. This review focuses on the timing of, and indications for, an invasive strategy after fibrinolytic therapy, including that for failed pharmacological reperfusion.

Nephrotoxic effects of iodixanol and iopromide in patients with abnormal renal function receiving N-acetylcysteine and hydration before coronary angiography and intervention: a randomized trial.

BACKGROUND: The use of contrast agents during coronary intervention can result in nephropathy, particularly in patients with renal dysfunction. We aimed to determine whether the use of iso-osmolar iodixanol is less nephrotoxic than that of low-osmolar iopromide when patients are adequately prehydrated and have received N-acetylcysteine. METHODS: We conducted a randomized, double-blind, multicentre study of patients with impaired renal function undergoing a coronary interventional procedure. Primary end-point was the incidence of contrast-induced nephropathy (CIN) on day 2, defined as an increase in serum creatinine concentration of > or =44 micromol/L (0.5 mg/dL) or by a relative increase of > or =25% from baseline. Secondary end-points included peak increase in serum creatinine between baseline and day 7. RESULTS: Of 191 patients recruited, 15% (95% CI: 8-22) of the patients receiving iopromide and 12% (95% CI: 5-19) of the patients receiving iodixanol developed CIN (95% CI of the difference: 13 to -7, P = 0.56). When including peak serum creatinine on day 7, CIN developed in 23% of patients receiving iopromide and in 27% of patients receiving iodixanol (95% CI of the difference: 8 to -16, P = 0.48). The peak increase in serum creatinine concentration at day 7 was similar in both groups (patients receiving iopromide, 18.4 +/- 24.4 micromol/L, vs patients receiving iodixanol, 21.9 +/- 24.2 micromol/L; P = 0.33). CONCLUSION: There remains a high incidence of CIN despite prehydration and routine use of N-acetylcysteine in patients with pre-existing renal dysfunction undergoing coronary interventional procedures. Although our study is underpowered, iodixanol was not associated with a statistically significant lower incidence of CIN when compared with iopromide.

The pharmaco-invasive approach to STEMI: when should fibrinolytic-treated patients go to the "cath lab"?

Although primary percutaneous coronary intervention (PCI) in clinical trials has lower rates of reinfarction, stroke and mortality than fibrinolytic therapy, because of system delays in routine practice, field triage and prehospital administration of fibrinolytic therapy may lead to similar clinical outcomes, especially in those patients who present in the first 2 h after symptom onset. Necessary for these outcomes is the liberal use of both rescue PCI and in-hospital revascularisation. Non-invasive prediction of failed reperfusion may be enhanced by the use of ST recovery, patient characteristics and troponin T levels, measured by point-of-care assays. This review focuses on the timing of, and indications for, an invasive strategy after fibrinolytic therapy, including that for failed pharmacological reperfusion.

Relationship of QRS duration at baseline and changes over 60 min after fibrinolysis to 30-day mortality with different locations of ST elevation myocardial infarction: results from the Hirulog and Early Reperfusion or Occlusion-2 trial.

OBJECTIVE: To discern if the prognostic meaning of QRS prolongation differs according to the location of ST elevation acute myocardial infarction DESIGN: Measuring QRS duration in patients with normal conduction or right bundle branch block SETTING: HERO-2 trial with prospective collection of electrocardiograms at randomisation and at 60 min after fibrinolytic therapy PATIENTS: 12 456 patients with normal conduction at both randomisation and 60-min time points and 510 with right bundle branch block (RBBB) at both time points MAIN OUTCOME MEASURE: 30-day mortality. RESULTS: On the baseline ECG, there was a positive association between QRS duration and 30-day mortality with anterior acute myocardial infarction (AMI) (p<0.0001 for those with normal conduction and = 0.007 for those with RBBB) but not with inferior AMI (p = 0.29 and p = 0.32, respectively). For anterior AMI, with or without RBBB, an increment of 20 ms increase in QRS duration predicted a significant 30-40% relative increase in 30-day mortality both before and after adjusting for clinical and ECG variables including baseline ST elevation and presence of Q waves. The association was not present for inferior AMI. Changes in QRS duration over 60 min after fibrinolytic therapy were uncommon and unrelated to mortality. CONCLUSION: Baseline QRS duration independently stratifies 30-day mortality in patients with anterior AMI, even when unaccompanied by RBBB, but does not stratify mortality risk in patients with inferior AMI.

Variations in the use of emergency PCI for the treatment of re-infarction following intravenous fibrinolytic therapy: impact on outcomes in HERO-2.

BACKGROUND: Patients who suffer re-infarction during initial hospitalization for ST-elevation myocardial infarction (STEMI) have decreased survival compared to patients without re-infarction, so treatment of re-infarction may influence survival. METHODS AND RESULTS: To determine whether the utilization of reperfusion therapies varied within 12 h of re-infarction and was associated with 30-day mortality, we studied 552 patients with re-infarction of 17,073 patients with STEMI enrolled in HERO-2 in five regions (Russia, Eastern Europe, Western Countries, Asia, and Latin America). Patients presenting within 6 h of symptom-onset were randomized to receive either bivalirudin or unfractionated heparin intravenously just prior to streptokinase. Re-infarction occurred in 2.8 and 3.6% of bivalirudin and heparin treated patients, respectively (P = 0.004), but treatment assignment did not influence mortality after re-infarction. Patients with re-infarction had a higher 30-day mortality than those without re-infarction (24 vs. 10%; P < 0.001 by Cox model). Within 12 h of re-infarction, fibrinolytic therapy was administered to 12.0 and 8.2% underwent percutaneous coronary intervention (PCI); these two treatments were more frequently utilized in patients from Western countries (n = 112), compared to patients from other countries (n = 440) (34.8 and 16.1% compared to 6.1 and 6.1%, respectively, P < 0.001). Mortality was 15% in patients receiving reperfusion therapy for re-infarction and 27% for those with conservative management, hazard ratio (HR) 0.53 (95% CI 0.32-0.88), P = 0.01. In multiple Cox regression analysis which included adjustment for clinical variables and randomized treatment assignment, 30-day mortality after re-infarction varied by region (highest Latin America 29%, lowest Western countries 15%; P = 0.01). Other independent prognostic factors included age, time from randomization to re-infarction, and Killip class at randomization. The HR for PCI treatment of re-infarction was 0.18 [(95% CI 0.04-0.76), P = 0.02] in analyses which excluded deaths within 12 h. CONCLUSION: Treatment of re-infarction with reperfusion therapies was markedly under-utilized, especially in non-western countries. PCI for re-infarction, in particular, was associated with a lower 30-day mortality, which may reflect both patient selection and effects of treatment.

End points in clinical trials: are they moving the goalposts?

In selecting and defining composite end points in clinical trials, are we trading off clinical significance for statistical significance?

Lack of association between baseline plasma homocysteine concentrations and restenosis rates after a first elective percutaneous coronary intervention without stenting.

OBJECTIVE: To evaluate the association between baseline homocysteine concentrations and restenosis rates in patients electively undergoing their first percutaneous coronary intervention (PCI) without stenting. DESIGN: Prospective, single centre, observational study. SETTING AND PATIENTS: Patients electively undergoing their first PCI without stenting at a tertiary referral centre between 1990 and 1998. METHODS: Blood samples were collected from all patients at baseline and assayed to determine the patients' homocysteine concentrations. Patients whose PCI was successful underwent repeat angiography at a median of 6.4 (interquartile range 6-6.8) months. Their baseline and follow up angiograms were compared by quantitative coronary angiography to assess the incidence of restenosis. For the analysis, the patients were divided into two groups based on whether their baseline homocysteine concentrations were above or below the median value. These two groups were compared to determine whether there was any association between their baseline homocysteine concentrations and the incidence of restenosis at six months. RESULTS: 134 patients had a successful first PCI without stenting (involving 200 lesions). At six month angiography, restenosis was observed in 33 patients (49.3%) with baseline homocysteine concentrations above the median value and in 31 patients (46.3%) with concentrations below the median value (p = 0.74). There was no difference in the percentage of lesions developing restenosis (38 (39.6%) v 40 (38.5%), respectively, p = 0.87) or late lumen loss (0.40 mm v 0.31 mm, respectively, p = 0.24). On multivariable analysis, there was no association between homocysteine concentrations and late lumen loss (r = -0.11, p = 0.11) or the percentage diameter stenosis at follow up (r = -0.07, p = 0.32). CONCLUSION: Baseline homocysteine concentrations were not associated with six month restenosis rates in patients electively undergoing their first PCI without stenting.

Thrombotic risk in patients with aortic bioprostheses.

Thrombosis of Mosaic aortic valve bioprostheses occurring at more than one month after surgery occurs in 0.8% (95% CI 0.33-1.67%) of patients. In the two cases reported here, each patient had risk factors for thrombus formation, namely severe left ventricular impairment in one patient, while the other patient was heterozygous for prothrombin variant G20210A. The cases were treated successfully, by thrombolytic therapy with streptokinase in the first case, and by repeat aortic valve replacement in the second case. Thrombosis of bioprosthetic valves in the aortic position is rare, and a period of anticoagulation postoperatively does not invariably protect against this serious complication. In conclusion, patients with risk factors for thrombus formation should be considered for long-term anticoagulation.

Associations between ST depression, four year mortality, and in-hospital revascularisation in unselected patients with non-ST elevation acute coronary syndromes.

OBJECTIVE: To determine the associations between changes on the presenting ECG, in-hospital revascularisation, and four year mortality in patients with non-ST elevation acute coronary syndromes. DESIGN: Prospective evaluation of all consecutive patients admitted in 1993 to the Green Lane Hospital coronary care unit, Auckland, New Zealand. Late follow up was undertaken at a median of 52 months. The ECGs were analysed after the hospital admission. SETTING: Tertiary referral centre with direct local coronary care unit admissions. INTERVENTIONS: Patients underwent physician recommended in-hospital revascularisation or initial conservative management. RESULTS: The four year survival was 88% in the 115 patients who underwent revascularisation (65 (19%) percutaneous and 53 (16%) surgical revascularisation), compared with 75% in 316 patients managed conservatively (p = 0.024). Four year survival for patients undergoing revascularisation versus initial conservative management with respect to ECG groups was: no ECG changes (n = 101), 97% v 92% (p = 0.35); T wave inversion or 0.5 mm ST depression (n = 108), 89% v 78% (p = 0.18); ST depression > or = 1 mm (n = 122), 80% v 58% (p = 0.014); chi2 = 29, p < 0.001 for the linear trend across the groups. On multivariate analysis, independent predictors of four year mortality were: age (odds ratio (OR) 1.05, 95% confidence interval (CI) 1.01 to 1.08; p = 0.0046); ECG group (OR 1.88, 95% CI 1.21 to 2.95; p = 0.043); radiological pulmonary oedema (OR 2.81, 95% CI 1.18 to 7.05; p = 0.025); and revascularisation (OR 0.43, 95% CI 0.20 to 0.90; p = 0.023). CONCLUSIONS: Among unselected patients with non-ST elevation acute coronary syndromes, in-hospital revascularisation is associated with decreased mortality at up to four years after admission. This association appears greater in patients with ST depression of > or = 1 mm on the presenting ECG.

Slowed ST segment recovery despite early infarct artery patency in patients with Q waves at presentation with a first acute myocardial infarction. Implications of initial Q waves on myocyte reperfusion.

BACKGROUND: The presence of Q waves at presentation with a first acute myocardial infarction reflects a more advanced stage of the infarction process. When infarct-related artery patency (Thrombolysis in Myocardial Infarction 2 or 3 flow) is restored, resolution of ST segment elevation indicating successful myocyte reperfusion may differ according to how far the infarction process has progressed. METHODS AND RESULTS: In 144 patients with a first acute myocardial infarction treated with streptokinase in the first Hirulog Early Reperfusion Occlusion trial, information was obtained from continuous ST segment monitoring, the presenting electrocardiogram and early angiography performed at a median time of 99 min after the commencement of streptokinase (interquartile range 89-108 min). We determined how many patients had 50% ST recovery within 120 min and in how many cases it was sustained over 4h. In the 109 patients with patent infarct-related arteries, 50% ST recovery occurred in 95% of patients without vs 80% of those with initial Q waves (P=0.03), and sustained ST recovery occurred in 67% of patients without vs 47% of those with initial Q waves (P=0.03). On multivariate analysis including the time from symptom onset to streptokinase therapy, the presence of Q waves at presentation was the only predictor of failure to achieve 50% ST recovery (odds ratio 5.08, 95% confidence interval 1.29-20.01, P=0.02). TIMI 2 flow, as opposed to TIMI 3 flow, was the only predictor of failure to achieve stable ST recovery (odds ratio 2.63, 95% confidence interval 1.15-5.88,P =0.02). CONCLUSION: The presence of initial Q waves predicts slower and less complete ST recovery, reflecting reduced myocyte reperfusion, even in those with early infarct artery patency. These patients may be targeted for new therapeutic strategies to improve microvascular reperfusion.

Usefulness of the presenting electrocardiogram in predicting myocardial salvage with thrombolytic therapy in patients with a first acute myocardial infarction.

AIMS: Patients with Q waves and T-wave inversion are generally at a later stage of the infarction process than patients without these changes. Our aim was to investigate whether a single assessment of electrocardiographic parameters at presentation would predict the proportion of myocardium salvageable by thrombolytic therapy. METHODS AND RESULTS: Electrocardiographic algorithms to calculate the potential and final infarct size have been developed and allow the proportion of myocardium salvageable with therapy to be calculated. This was measured in 146 patients with acute myocardial infarction who had angiography at a median of 91 min after streptokinase. The relationship between myocardial salvage and the electrocardiographic parameters at presentation (Q waves, T-wave inversion, quantitative ST segment changes, and the initial QRS score), was examined together with the 90-min angiographic parameters (TIMI flow grade and collateral grade), clinical parameters (haemodynamics and age), and time to therapy. Parameters that correlated with myocardial salvage included the initial QRS score (r=-0.56, P<0.0001), Q wave grade (r=-0.36, P<0.0001), number of leads with ST depression (r=0.28, P<0.001), maximum ST depression (r=0.27, P<0.01), T-inversion grade (r=-0.26, P<0.01), and TIMI flow grade at 90 min (r=0.21, P<0.02). The time from symptom onset to thrombolytic therapy did not correlate with salvage (r=-0.09). On multivariate analysis, only the initial QRS score and T-inversion grade on the initial electrocardiogram were independent predictors of salvage (multivariate r using both variables combined=0.57, P<0.001). CONCLUSIONS: The QRS score and T-wave inversion grade on the presenting electrocardiogram provide important information in predicting myocardial salvage. These parameters may help triage patients to appropriate therapies.

Corrected TIMI frame counts correlate with stenosis severity and infarct zone wall motion after thrombolytic therapy.

BACKGROUND: The majority of patients with patent infarct-related arteries after thrombolytic therapy have slower than normal flow, which relates to myocardial perfusion. METHODS: To evaluate the relationships between blood levels of creatine kinase (CK) and the corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (CTFC), infarct artery stenosis, and left ventricular function, we studied 397 patients with a first myocardial infarction who underwent angiography at 3 weeks. TIMI flow grades, the CTFC, infarct artery stenosis, and infarct zone wall motion (by contrast ventriculography using the centerline method) were assessed, and CK levels (in units per liter) were measured hourly for the first 4 hours after streptokinase (1.5 x 10(6) U over 30-60 minutes) and then every 4 hours over the next 20 hours, all blinded to treatment and outcome. RESULTS: Infarct artery stenosis and the CTFC, assessed as continuous variables, correlated in patients with patent infarct arteries (r = 0.33, P <.001). Also, there was a significant correlation between the CTFC and the sum of hypokinetic chords in the infarct zone (r = 0.15, P =.01). Patients with total occlusion or markedly slowed infarct artery flow (CTFC >100) had a higher fraction of chords with wall motion >2 SDs below normal (0.65 [0.41, 0.80] vs 0.37 [0.0, 0.67]) compared with patients with normal flow (CTFC < or =27) (P <.001). The rates of increase of median CK levels with respect to TIMI flow grades were 342 U/L/h for TIMI 3 versus 212 U/L/h for TIMI 2 versus 140 U/L/h for TIMI 0-1 (P <.0001). CONCLUSIONS: Prolonged corrected TIMI frame counts correlate with stenosis severity in the infarct artery after infarction, infarct zone regional wall motion, and CK levels.

Prevalence of factor V Leiden and prothrombin variant G20210A in patients age <50 years with no significant stenoses at angiography three to four weeks after myocardial infarction.

OBJECTIVES: We sought to determine the frequencies of factor V Leiden and prothrombin variant G20210A in patients age <50 years with no significant coronary stenoses three to four weeks after myocardial infarction (MI). BACKGROUND: Factor V Leiden and prothrombin variant G20210A occur frequently in patients with venous thromboembolism. However, the contribution of these mutations to the development of MI requires clarification. METHODS: The frequencies of factor V Leiden and prothrombin variant G20210A were determined in 41 patients age <50 years who had "normal" or "near normal" coronary arteries (no stenosis >50%) at angiography three to four weeks after MI (the study group) and compared with those in 114 patients who had at least one angiographic stenosis >50% after MI (the control group). Patients age > or =50 years with, or without, stenoses were also studied. RESULTS: The frequency of factor V Leiden was 14.6% in patients age <50 years in the study group compared with 3.6% in patients in the control group (odds ratio [OR] 4.7 [95% confidence interval (CI) 1.3-17.7], p = 0.02). The frequency of the prothrombin variant G20210A was 7.3% in the study group compared with 1.8% in the control group (OR 4.4 [95% CI 0.7-27.5], p = 0.12). One or both mutations were present in 8 of the 41 patients (19.5%) age <50 years in the study group compared with 6 of the 114 patients (5.5%) in the control group (OR 4.4 [95% CI 1.4-13.5], p = 0.01). In all 271 patients (irrespective of age) with normal arteries, the frequency of factor V Leiden was 11.7% (7/60) compared with 4.3% (9/211) in patients with at least one >50% stenosis (OR 2.9 [95% CI 1.1-8.3], p = 0.04), and the frequency of prothrombin variant G20210A was 6.7% (4/60) compared with 1.4% (3/211) (OR 4.9 [95% CI 1.1-22.8], p = 0.04), respectively. CONCLUSIONS: The frequencies of factor V Leiden and/or prothrombin variant G20210A are increased in patients age <50 years with normal or near normal coronary arteries after MI.

Angiographic findings and clinical correlates in patients with cardiogenic shock complicating acute myocardial infarction: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK?

OBJECTIVES: We sought to delineate the angiographic findings, clinical correlates and in-hospital outcomes in patients with cardiogenic shock (CS) complicating acute myocardial infarction. BACKGROUND: Patients with CS complicating acute myocardial infarction carry a grave prognosis. Detailed angiographic findings in a large, prospectively identified cohort of patients with CS are currently lacking. METHODS: We compared the clinical characteristics, angiographic findings, and in-hospital outcomes of 717 patients selected to undergo angiography and 442 not selected, overall and by shock etiology: left or right ventricular failure versus mechanical complications. RESULTS: Patients who underwent angiography had lower baseline risk and a better hemodynamic profile than those who did not. Overall, 15.5% of the patients had significant left main lesions on angiography, and 53.4% had three-vessel disease, with higher rates of both for those with ventricular failure, compared with patients who had mechanical complications. Among patients who underwent angiography, those with ventricular failure had significantly lower in-hospital mortality than patients with mechanical complications (45.2% vs. 57.0%; p = 0.021). Importantly, for patients with ventricular failure, in-hospital mortality also correlated with disease severity: 35.0% for no or single-vessel disease versus 50.8% for three-vessel disease. Furthermore, mortality was associated with the culprit lesion location (78.6% in left main lesion, 69.7% in saphenous vein graft lesions, 42.4% in circumflex lesions, 42.3% in left anterior descending lesions, and 37.4% in right coronary artery lesions), and Thrombolysis In Myocardial Infarction (TIMI) flow grade (46.5% in TIMI 0/1, 49.4% in TIMI 2 and 26% in TIMI 3). CONCLUSIONS: Patients who underwent angiographic study in the SHOCK Trial Registry had a more benign cardiac risk profile, more favorable hemodynamic findings and lower in-hospital mortality than those for whom angiograms were not obtained. Patients with CS caused by ventricular failure had more severe atherosclerosis, and a different distribution of culprit vessel involvement but lower in-hospital mortality, than those with mechanical complications. Overall in-hospital survival correlates with the extent of coronary artery obstructions, location of culprit lesion and baseline coronary TIMI flow grade.

Cardiogenic shock with non-ST-segment elevation myocardial infarction: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded coronaries for Cardiogenic shocK?

OBJECTIVES: We sought to determine the outcomes of patients with cardiogenic shock (CS) complicating non-ST-segment elevation acute myocardial infarction (MI). BACKGROUND: Such patients represent a high-risk (ST-segment depression) or low-risk (normal or nonspecific electrocardiographic findings) group for whom optimal therapy, particularly in the setting of shock, is unknown. METHODS: We assessed characteristics and outcomes of 881 patients with CS due to predominant left ventricular (LV) dysfunction in the SHOCK Trial Registry. RESULTS: Patients with non-ST-segment elevation MI (n = 152) were significantly older and had significantly more prior MI, heart failure, azotemia, bypass surgery, and peripheral vascular disease than patients with ST-elevation MI (n = 729). On average, the groups had similar in-hospital LV ejection fractions (approximately 30%), but patients with non-ST-elevation MI had a lower highest creatine kinase and were more likely to have triple-vessel disease. Among patients selected for coronary angiography, the left circumflex artery was the culprit vessel in 34.6% of non-ST-elevation versus 13.4% of ST-elevation MI patients (p = 0.001). Despite having more recurrent ischemia (25.7% vs. 17.4%, p = 0.058), non-ST-elevation patients underwent angiography less often (52.6% vs. 64.1%, p = 0.010). The proportion undergoing revascularization was similar (36.8% for non-ST-elevation vs. 41.9% ST-elevation MI, p = 0.277). In-hospital mortality also was similar in the two groups (62.5% for non-ST-elevation vs. 60.4% ST-elevation MI). After adjustment, ST-segment elevation MI did not independently predict in-hospital mortality (odds ratio, 1.30; 95% confidence interval, 0.83 to 2.02; p = 0.252). CONCLUSIONS: Patients with CS and non-ST-segment elevation MI have a higher-risk profile than shock patients with ST-segment elevation, but similar in-hospital mortality. More recurrent ischemia and less angiography represent opportunities for earlier intervention, and early reperfusion therapy for circumflex artery occlusion should be considered when non-ST-elevation MI causes CS.