International Expert Consensus Document on Takotsubo Syndrome (Part I): Clinical Characteristics, Diagnostic Criteria, and Pathophysiology

Takotsubo syndrome (TTS) is a poorly recognized heart disease that was initially regarded as a benign condition. Recently, it has been shown that TTS may be associated with severe clinical complications including death and that its prevalence is probably underestimated. Since current guidelines on TTS are lacking, it appears timely and important to provide an expert consensus statement on TTS. The clinical expert consensus document part I summarizes the current state of knowledge on clinical presentation and characteristics of TTS and agrees on controversies surrounding TTS such as nomenclature, different TTS types, role of coronary artery disease, and etiology. This consensus also proposes new diagnostic criteria based on current knowledge to improve diagnostic accuracy.

Thrombus aspiration during ST-segment elevation myocardial infarction

BACKGROUND

The clinical effect of routine intracoronary thrombus aspiration before primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is uncertain. We aimed to evaluate whether thrombus aspiration reduces mortality.

METHODS

We conducted a multicenter, prospective, randomized, controlled, open-label clinical trial, with enrollment of patients from the national comprehensive Swedish Coronary Angiography and Angioplasty Registry (SCAAR) and end points evaluated through national registries. A total of 7244 patients with STEMI undergoing PCI were randomly assigned to manual thrombus aspiration followed by PCI or to PCI only. The primary end point was all-cause mortality at 30 days.

RESULTS

No patients were lost to follow-up. Death from any cause occurred in 2.8% of the patients in the thrombus-aspiration group (103 of 3621), as compared with 3.0% in the PCI-only group (110 of 3623) (hazard ratio, 0.94; 95% confidence interval [CI], 0.72 to 1.22; P=0.63). The rates of hospitalization for recurrent myocardial infarction at 30 days were 0.5% and 0.9% in the two groups, respectively (hazard ratio, 0.61; 95% CI, 0.34 to 1.07; P=0.09), and the rates of stent thrombosis were 0.2% and 0.5%, respectively (hazard ratio, 0.47; 95% CI, 0.20 to 1.02; P=0.06). There were no significant differences between the groups with respect to the rate of stroke or neurologic complications at the time of discharge (P=0.87). The results were consistent across all major prespecified subgroups, including subgroups defined according to thrombus burden and coronary flow before PCI.

CONCLUSIONS

Routine thrombus aspiration before PCI as compared with PCI alone did not reduce 30-day mortality among patients with STEMI. (Funded by the Swedish Research Council and others; ClinicalTrials.gov number, NCT01093404.).

Current state of knowledge on Takotsubo syndrome: a Position Statement from the Taskforce on Takotsubo Syndrome of the Heart Failure Association of the European Society of Cardiology

Takotsubo syndrome is an acute reversible heart failure syndrome that is increasingly recognized in modern cardiology practice. This Position Statement from the European Society of Cardiology Heart Failure Association provides a comprehensive review of the various clinical and pathophysiological facets of Takotsubo syndrome, including nomenclature, definition, and diagnosis, primary and secondary clinical subtypes, anatomical variants, triggers, epidemiology, pathophysiology, clinical presentation, complications, prognosis, clinical investigations, and treatment approaches. Novel structured approaches to diagnosis, risk stratification, and management are presented, with new algorithms to aid decision-making by practising clinicians. These also cover more complex areas (e.g. uncertain diagnosis and delayed presentation) and the management of complex cases with ongoing symptoms after recovery, recurrent episodes, or spontaneous presentation. The unmet needs and future directions for research in this syndrome are also discussed.

Instantaneous Wave-free Ratio versus Fractional Flow Reserve to Guide PCI

BACKGROUND

The instantaneous wave-free ratio (iFR) is an index used to assess the severity of coronary-artery stenosis. The index has been tested against fractional flow reserve (FFR) in small trials, and the two measures have been found to have similar diagnostic accuracy. However, studies of clinical outcomes associated with the use of iFR are lacking. We aimed to evaluate whether iFR is noninferior to FFR with respect to the rate of subsequent major adverse cardiac events.

METHODS

We conducted a multicenter, randomized, controlled, open-label clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2037 participants with stable angina or an acute coronary syndrome who had an indication for physiologically guided assessment of coronary-artery stenosis were randomly assigned to undergo revascularization guided by either iFR or FFR. The primary end point was the rate of a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization within 12 months after the procedure.

RESULTS

A primary end-point event occurred in 68 of 1012 patients (6.7%) in the iFR group and in 61 of 1007 (6.1%) in the FFR group (difference in event rates, 0.7 percentage points; 95% confidence interval [CI], -1.5 to 2.8; P=0.007 for noninferiority; hazard ratio, 1.12; 95% CI, 0.79 to 1.58; P=0.53); the upper limit of the 95% confidence interval for the difference in event rates fell within the prespecified noninferiority margin of 3.2 percentage points. The results were similar among major subgroups. The rates of myocardial infarction, target-lesion revascularization, restenosis, and stent thrombosis did not differ significantly between the two groups. A significantly higher proportion of patients in the FFR group than in the iFR group reported chest discomfort during the procedure.

CONCLUSIONS

Among patients with stable angina or an acute coronary syndrome, an iFR-guided revascularization strategy was noninferior to an FFR-guided revascularization strategy with respect to the rate of major adverse cardiac events at 12 months. (Funded by Philips Volcano; iFR SWEDEHEART ClinicalTrials.gov number, NCT02166736 .).

Fractional Flow Reserve-Guided Multivessel Angioplasty in Myocardial Infarction

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI), the use of percutaneous coronary intervention (PCI) to restore blood flow in an infarct-related coronary artery improves outcomes. The use of PCI in non-infarct-related coronary arteries remains controversial.

METHODS

We randomly assigned 885 patients with STEMI and multivessel disease who had undergone primary PCI of an infarct-related coronary artery in a 1:2 ratio to undergo complete revascularization of non-infarct-related coronary arteries guided by fractional flow reserve (FFR) (295 patients) or to undergo no revascularization of non-infarct-related coronary arteries (590 patients). The FFR procedure was performed in both groups, but in the latter group, both the patients and their cardiologist were unaware of the findings on FFR. The primary end point was a composite of death from any cause, nonfatal myocardial infarction, revascularization, and cerebrovascular events at 12 months. Clinically indicated elective revascularizations performed within 45 days after primary PCI were not counted as events in the group receiving PCI for an infarct-related coronary artery only.

RESULTS

The primary outcome occurred in 23 patients in the complete-revascularization group and in 121 patients in the infarct-artery-only group that did not receive complete revascularization, a finding that translates to 8 and 21 events per 100 patients, respectively (hazard ratio, 0.35; 95% confidence interval [CI], 0.22 to 0.55; P<0.001). Death occurred in 4 patients in the complete-revascularization group and in 10 patients in the infarct-artery-only group (1.4% vs. 1.7%) (hazard ratio, 0.80; 95% CI, 0.25 to 2.56), myocardial infarction in 7 and 28 patients, respectively (2.4% vs. 4.7%) (hazard ratio, 0.50; 95% CI, 0.22 to 1.13), revascularization in 18 and 103 patients (6.1% vs. 17.5%) (hazard ratio, 0.32; 95% CI, 0.20 to 0.54), and cerebrovascular events in 0 and 4 patients (0 vs. 0.7%). An FFR-related serious adverse event occurred in 2 patients (both in the group receiving infarct-related treatment only).

CONCLUSIONS

In patients with STEMI and multivessel disease who underwent primary PCI of an infarct-related artery, the addition of FFR-guided complete revascularization of non-infarct-related arteries in the acute setting resulted in a risk of a composite cardiovascular outcome that was lower than the risk among those who were treated for the infarct-related artery only. This finding was mainly supported by a reduction in subsequent revascularizations. (Funded by Maasstad Cardiovascular Research and others; Compare-Acute ClinicalTrials.gov number, NCT01399736 .).

International Expert Consensus Document on Takotsubo Syndrome (Part II): Diagnostic Workup, Outcome, and Management

The clinical expert consensus statement on takotsubo syndrome (TTS) part II focuses on the diagnostic workup, outcome, and management. The recommendations are based on interpretation of the limited clinical trial data currently available and experience of international TTS experts. It summarizes the diagnostic approach, which may facilitate correct and timely diagnosis. Furthermore, the document covers areas where controversies still exist in risk stratification and management of TTS. Based on available data the document provides recommendations on optimal care of such patients for practising physicians.

Bivalirudin or Unfractionated Heparin in Acute Coronary Syndromes

BACKGROUND

Conflicting evidence exists on the efficacy and safety of bivalirudin administered as part of percutaneous coronary intervention (PCI) in patients with an acute coronary syndrome.

METHODS

We randomly assigned 7213 patients with an acute coronary syndrome for whom PCI was anticipated to receive either bivalirudin or unfractionated heparin. Patients in the bivalirudin group were subsequently randomly assigned to receive or not to receive a post-PCI bivalirudin infusion. Primary outcomes for the comparison between bivalirudin and heparin were the occurrence of major adverse cardiovascular events (a composite of death, myocardial infarction, or stroke) and net adverse clinical events (a composite of major bleeding or a major adverse cardiovascular event). The primary outcome for the comparison of a post-PCI bivalirudin infusion with no post-PCI infusion was a composite of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events.

RESULTS

The rate of major adverse cardiovascular events was not significantly lower with bivalirudin than with heparin (10.3% and 10.9%, respectively; relative risk, 0.94; 95% confidence interval [CI], 0.81 to 1.09; P=0.44), nor was the rate of net adverse clinical events (11.2% and 12.4%, respectively; relative risk, 0.89; 95% CI, 0.78 to 1.03; P=0.12). Post-PCI bivalirudin infusion, as compared with no infusion, did not significantly decrease the rate of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events (11.0% and 11.9%, respectively; relative risk, 0.91; 95% CI, 0.74 to 1.11; P=0.34).

CONCLUSIONS

In patients with an acute coronary syndrome, the rates of major adverse cardiovascular events and net adverse clinical events were not significantly lower with bivalirudin than with unfractionated heparin. The rate of the composite of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events was not significantly lower with a post-PCI bivalirudin infusion than with no post-PCI infusion. (Funded by the Medicines Company and Terumo Medical; MATRIX ClinicalTrials.gov number, NCT01433627.).

Outcomes 1 year after thrombus aspiration for myocardial infarction

BACKGROUND

Routine intracoronary thrombus aspiration before primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) has not been proved to reduce short-term mortality. We evaluated clinical outcomes at 1 year after thrombus aspiration.

METHODS

We randomly assigned 7244 patients with STEMI to undergo manual thrombus aspiration followed by PCI or to undergo PCI alone, in a registry-based, randomized clinical trial. The primary end point of all-cause mortality at 30 days has been reported previously. Death from any cause at 1 year was a prespecified secondary end point of the trial.

RESULTS

No patients were lost to follow-up. Death from any cause occurred in 5.3% of the patients (191 of 3621 patients) in the thrombus-aspiration group, as compared with 5.6% (202 of 3623) in the PCI-only group (hazard ratio, 0.94; 95% confidence interval [CI], 0.78 to 1.15; P=0.57). Rehospitalization for myocardial infarction at 1 year occurred in 2.7% and 2.7% of the patients, respectively (hazard ratio, 0.97; 95% CI, 0.73 to 1.28; P=0.81), and stent thrombosis in 0.7% and 0.9%, respectively (hazard ratio, 0.84; 95% CI, 0.50 to 1.40; P=0.51). The composite of death from any cause, rehospitalization for myocardial infarction, or stent thrombosis occurred in 8.0% and 8.5% of the patients, respectively (hazard ratio, 0.94; 95% CI, 0.80 to 1.11; P=0.48). The results were consistent across all the major subgroups, including grade of thrombus burden and coronary flow before PCI.

CONCLUSIONS

Routine thrombus aspiration before PCI in patients with STEMI did not reduce the rate of death from any cause or the composite of death from any cause, rehospitalization for myocardial infarction, or stent thrombosis at 1 year. (Funded by the Swedish Research Council and others; TASTE ClinicalTrials.gov number, NCT01093404.).

Identification of vulnerable plaques and patients by intracoronary near-infrared spectroscopy and ultrasound (PROSPECT II): a prospective natural history study

BACKGROUND

Near-infrared spectroscopy (NIRS) and intravascular ultrasound are promising imaging modalities to identify non-obstructive plaques likely to cause coronary-related events. We aimed to assess whether combined NIRS and intravascular ultrasound can identify high-risk plaques and patients that are at risk for future major adverse cardiac events (MACEs).

METHODS

PROSPECT II is an investigator-sponsored, multicentre, prospective natural history study done at 14 university hospitals and two community hospitals in Denmark, Norway, and Sweden. We recruited patients of any age with recent (within past 4 weeks) myocardial infarction. After treatment of all flow-limiting coronary lesions, three-vessel imaging was done with a combined NIRS and intravascular ultrasound catheter. Untreated lesions (also known as non-culprit lesions) were identified by intravascular ultrasound and their lipid content was assessed by NIRS. The primary outcome was the covariate-adjusted rate of MACEs (the composite of cardiac death, myocardial infarction, unstable angina, or progressive angina) arising from untreated non-culprit lesions during follow-up. The relations between plaques with high lipid content, large plaque burden, and small lumen areas and patient-level and lesion-level events were determined. This trial is registered with ClinicalTrials.gov, NCT02171065.

FINDINGS

Between June 10, 2014, and Dec 20, 2017, 3629 non-culprit lesions were characterised in 898 patients (153 [17%] women, 745 [83%] men; median age 63 [IQR 55-70] years). Median follow-up was 3·7 (IQR 3·0-4·4) years. Adverse events within 4 years occurred in 112 (13·2%, 95% CI 11·0-15·6) of 898 patients, with 66 (8·0%, 95% CI 6·2-10·0) arising from 78 untreated non-culprit lesions (mean baseline angiographic diameter stenosis 46·9% [SD 15·9]). Highly lipidic lesions (851 [24%] of 3500 lesions, present in 520 [59%] of 884 patients) were an independent predictor of patient-level non-culprit lesion-related MACEs (adjusted odds ratio 2·27, 95% CI 1·25-4·13) and non-culprit lesion-specific MACEs (7·83, 4·12-14·89). Large plaque burden (787 [22%] of 3629 lesions, present in 530 [59%] of 898 patients) was also an independent predictor of non-culprit lesion-related MACEs. Lesions with both large plaque burden by intravascular ultrasound and large lipid-rich cores by NIRS had a 4-year non-culprit lesion-related MACE rate of 7·0% (95% CI 4·0-10·0). Patients in whom one or more such lesions were identified had a 4-year non-culprit lesion-related MACE rate of 13·2% (95% CI 9·4-17·6).

INTERPRETATION

Combined NIRS and intravascular ultrasound detects angiographically non-obstructive lesions with a high lipid content and large plaque burden that are at increased risk for future adverse cardiac outcomes.

FUNDING

Abbott Vascular, Infraredx, and The Medicines Company.

Oxygen Therapy in Suspected Acute Myocardial Infarction

BACKGROUND

The clinical effect of routine oxygen therapy in patients with suspected acute myocardial infarction who do not have hypoxemia at baseline is uncertain.

METHODS

In this registry-based randomized clinical trial, we used nationwide Swedish registries for patient enrollment and data collection. Patients with suspected myocardial infarction and an oxygen saturation of 90% or higher were randomly assigned to receive either supplemental oxygen (6 liters per minute for 6 to 12 hours, delivered through an open face mask) or ambient air.

RESULTS

A total of 6629 patients were enrolled. The median duration of oxygen therapy was 11.6 hours, and the median oxygen saturation at the end of the treatment period was 99% among patients assigned to oxygen and 97% among patients assigned to ambient air. Hypoxemia developed in 62 patients (1.9%) in the oxygen group, as compared with 254 patients (7.7%) in the ambient-air group. The median of the highest troponin level during hospitalization was 946.5 ng per liter in the oxygen group and 983.0 ng per liter in the ambient-air group. The primary end point of death from any cause within 1 year after randomization occurred in 5.0% of patients (166 of 3311) assigned to oxygen and in 5.1% of patients (168 of 3318) assigned to ambient air (hazard ratio, 0.97; 95% confidence interval [CI], 0.79 to 1.21; P=0.80). Rehospitalization with myocardial infarction within 1 year occurred in 126 patients (3.8%) assigned to oxygen and in 111 patients (3.3%) assigned to ambient air (hazard ratio, 1.13; 95% CI, 0.88 to 1.46; P=0.33). The results were consistent across all predefined subgroups.

CONCLUSIONS

Routine use of supplemental oxygen in patients with suspected myocardial infarction who did not have hypoxemia was not found to reduce 1-year all-cause mortality. (Funded by the Swedish Heart-Lung Foundation and others; DETO2X-AMI ClinicalTrials.gov number, NCT01787110 .).

Bivalirudin versus Heparin Monotherapy in Myocardial Infarction

BACKGROUND

The comparative efficacy of various anticoagulation strategies has not been clearly established in patients with acute myocardial infarction who are undergoing percutaneous coronary intervention (PCI) according to current practice, which includes the use of radial-artery access for PCI and administration of potent P2Y₁₂ inhibitors without the planned use of glycoprotein IIb/IIIa inhibitors.

METHODS

In this multicenter, randomized, registry-based, open-label clinical trial, we enrolled patients with either ST-segment elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI) who were undergoing PCI and receiving treatment with a potent P2Y₁₂ inhibitor (ticagrelor, prasugrel, or cangrelor) without the planned use of glycoprotein IIb/IIIa inhibitors. The patients were randomly assigned to receive bivalirudin or heparin during PCI, which was performed predominantly with the use of radial-artery access. The primary end point was a composite of death from any cause, myocardial infarction, or major bleeding during 180 days of follow-up.

RESULTS

A total of 6006 patients (3005 with STEMI and 3001 with NSTEMI) were enrolled in the trial. At 180 days, a primary end-point event had occurred in 12.3% of the patients (369 of 3004) in the bivalirudin group and in 12.8% (383 of 3002) in the heparin group (hazard ratio, 0.96; 95% confidence interval [CI], 0.83 to 1.10; P=0.54). The results were consistent between patients with STEMI and those with NSTEMI and across other major subgroups. Myocardial infarction occurred in 2.0% of the patients in the bivalirudin group and in 2.4% in the heparin group (hazard ratio, 0.84; 95% CI, 0.60 to 1.19; P=0.33), major bleeding in 8.6% and 8.6%, respectively (hazard ratio, 1.00; 95% CI, 0.84 to 1.19; P=0.98), definite stent thrombosis in 0.4% and 0.7%, respectively (hazard ratio, 0.54; 95% CI, 0.27 to 1.10; P=0.09), and death in 2.9% and 2.8%, respectively (hazard ratio, 1.05; 95% CI, 0.78 to 1.41; P=0.76).

CONCLUSIONS

Among patients undergoing PCI for myocardial infarction, the rate of the composite of death from any cause, myocardial infarction, or major bleeding was not lower among those who received bivalirudin than among those who received heparin monotherapy. (Funded by the Swedish Heart-Lung Foundation and others; VALIDATE-SWEDEHEART ClinicalTrialsRegister.eu number, 2012-005260-10 ; ClinicalTrials.gov number, NCT02311231 .).

Radial versus femoral access and bivalirudin versus unfractionated heparin in invasively managed patients with acute coronary syndrome (MATRIX): final 1-year results of a multicentre, randomised controlled trial

BACKGROUND

The Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox (MATRIX) programme was designed to assess the comparative safety and effectiveness of radial versus femoral access and of bivalirudin versus unfractionated heparin with optional glycoprotein IIb/IIIa inhibitors in patients with the whole spectrum of acute coronary syndrome undergoing invasive management. Here we describe the prespecified final 1-year outcomes of the entire programme.

METHODS

MATRIX was a programme of three nested, randomised, multicentre, open-label, superiority trials in patients with acute coronary syndrome in 78 hospitals in Italy, the Netherlands, Spain, and Sweden. Patients with ST-elevation myocardial infarction were simultaneously randomly assigned (1:1) before coronary angiography to radial or femoral access and to bivalirudin, with or without post-percutaneous coronary intervention infusion or unfractionated heparin (one-step inclusion). Patients with non-ST-elevation acute coronary syndrome were randomly assigned (1:1) before coronary angiography to radial or femoral access and, only if deemed eligible to percutaneous coronary intervention after angiography (two-step inclusion), entered the antithrombin type and treatment duration programmes. Randomisation sequences were computer generated, blocked, and stratified by intended new or current use of P2Y12 inhibitor (clopidogrel vs ticagrelor or prasugrel), and acute coronary syndrome type (ST-elevation myocardial infarction, troponin-positive, or troponin-negative non-ST-elevation acute coronary syndrome). Bivalirudin was given as a bolus of 0·75 mg/kg, followed immediately by an infusion of 1·75 mg/kg per h until completion of percutaneous coronary intervention. Heparin was given at 70-100 units per kg in patients not receiving glycoprotein IIb/IIIa inhibitors, and at 50-70 units per kg in patients receiving glycoprotein IIb/IIIa inhibitors. Clinical follow-up was done at 30 days and 1 year. Co-primary outcomes for MATRIX access and MATRIX antithrombin type were major adverse cardiovascular events, defined as the composite of all-cause mortality, myocardial infarction, or stroke up to 30 days; and net adverse clinical events, defined as the composite of non-coronary artery bypass graft-related major bleeding, or major adverse cardiovascular events up to 30 days. The primary outcome for MATRIX treatment duration was the composite of urgent target vessel revascularisation, definite stent thrombosis, or net adverse clinical events up to 30 days. Analyses were done according to the intention-to-treat principle. This trial is registered with ClinicalTrials.gov, number NCT01433627.

FINDINGS

Between Oct 11, 2011, and Nov 7, 2014, we randomly assigned 8404 patients to receive radial (4197 patients) or femoral (4207 patients) access. Of these 8404 patients, 7213 were included in the MATRIX antithrombin type study and were randomly assigned to bivalirudin (3610 patients) or heparin (3603 patients). Patients assigned to bivalirudin were included in the MATRIX treatment duration study, and were randomly assigned to post-procedure infusion (1799 patients) or no post-procedure infusion (1811 patients). At 1 year, major adverse cardiovascular events did not differ between patients assigned to radial access compared with those assigned to femoral access (14·2% vs 15·7%; rate ratio 0·89, 95% CI 0·80-1·00; p=0·0526), but net adverse clinical events were fewer with radial than with femoral access (15·2% vs 17·2%; 0·87, 0·78-0·97; p=0·0128). Compared with heparin, bivalirudin was not associated with fewer major adverse cardiovascular (15·8% vs 16·8%; 0·94, 0·83-1·05; p=0·28) or net adverse clinical events (17·0% vs 18·4%; 0·91, 0·81-1·02; p=0·10). The composite of urgent target vessel revascularisation, stent thrombosis, or net adverse clinical events did not differ with or without post-procedure bivalirudin infusion (17·4% vs 17·4%; 0·99, 0·84-1·16; p=0·90).

INTERPRETATION

In patients with acute coronary syndrome, radial access was associated with lower rates of net adverse clinical events compared with femoral access, but not major adverse cardiovascular events at 1 year. Bivalirudin with or without post-procedure infusion was not associated with lower rates of major adverse cardiovascular events or net adverse clinical events. Radial access should become the default approach in acute coronary syndrome patients undergoing invasive management.

FUNDING

Italian Society of Invasive Cardiology, The Medicines Company, Terumo, amd Canada Research Chairs Programme.

Rapid endovascular catheter core cooling combined with cold saline as an adjunct to percutaneous coronary intervention for the treatment of acute myocardial infarction. The CHILL-MI trial: a randomized controlled study of the use of central venous catheter core cooling combined with cold saline as an adjunct to percutaneous coronary intervention for the treatment of acute myocardial infarction

OBJECTIVES

The aim of this study was to confirm the cardioprotective effects of hypothermia using a combination of cold saline and endovascular cooling.

BACKGROUND

Hypothermia has been reported to reduce infarct size (IS) in patients with ST-segment elevation myocardial infarctions.

METHODS

In a multicenter study, 120 patients with ST-segment elevation myocardial infarctions (<6 h) scheduled to undergo percutaneous coronary intervention were randomized to hypothermia induced by the rapid infusion of 600 to 2,000 ml cold saline and endovascular cooling or standard of care. Hypothermia was initiated before percutaneous coronary intervention and continued for 1 h after reperfusion. The primary end point was IS as a percent of myocardium at risk (MaR), assessed by cardiac magnetic resonance imaging at 4 ± 2 days.

RESULTS

Mean times from symptom onset to randomization were 129 ± 56 min in patients receiving hypothermia and 132 ± 64 min in controls. Patients randomized to hypothermia achieved a core body temperature of 34.7°C before reperfusion, with a 9-min longer door-to-balloon time. Median IS/MaR was not significantly reduced (hypothermia: 40.5% [interquartile range: 29.3% to 57.8%; control: 46.6% [interquartile range: 37.8% to 63.4%]; relative reduction 13%; p = 0.15). The incidence of heart failure was lower with hypothermia at 45 ± 15 days (3% vs. 14%, p < 0.05), with no mortality. Exploratory analysis of early anterior infarctions (0 to 4 h) found a reduction in IS/MaR of 33% (p < 0.05) and an absolute reduction of IS/left ventricular volume of 6.2% (p = 0.15).

CONCLUSIONS

Hypothermia induced by cold saline and endovascular cooling was feasible and safe, and it rapidly reduced core temperature with minor reperfusion delay. The primary end point of IS/MaR was not significantly reduced. Lower incidence of heart failure and a possible effect in patients with early anterior ST-segment elevation myocardial infarctions need confirmation. (Efficacy of Endovascular Catheter Cooling Combined With Cold Saline for the Treatment of Acute Myocardial Infarction [CHILL-MI]; NCT01379261).

Pathophysiology of Takotsubo Syndrome: JACC State-of-the-Art Review

Takotsubo syndrome (TTS) has been a recognized clinical entity for 31 years, since its first description in 1990. TTS is now routinely diagnosed in patients who present with acute chest pain, electrocardiographic changes, troponin elevation, unobstructed coronary arteries, and a typical pattern of circumferential left ventricular wall motion abnormalities that usually involve the apical and midventricular myocardium. Increasing understanding of this intriguing syndrome stems from wider recognition, possible increasing frequency, and a rising number of publications focused on the pathophysiology in clinical and laboratory studies. A comprehensive understanding of TTS pathophysiology and evidence-based treatments are lacking, and specific and effective treatments are urgently required. This paper reviews the pathophysiology of this fascinating syndrome; what is known from both clinical and preclinical studies, including review of the evidence for microvascular dysfunction, myocardial beta-adrenergic signaling, inflammation, and electrophysiology; and where focused research needs to fill gaps in understanding TTS.

Fractional flow reserve-guided percutaneous coronary intervention vs. medical therapy for patients with stable coronary lesions: meta-analysis of individual patient data

Aims

To assess the effect of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) with contemporary drug-eluting stents on the composite of cardiac death or myocardial infarction (MI) vs. medical therapy in patients with stable coronary lesions.

Methods and results

We performed a systematic review and meta-analysis of individual patient data (IPD) of the three available randomized trials of contemporary FFR-guided PCI vs. medical therapy for patients with stable coronary lesions: FAME 2 (NCT01132495), DANAMI-3-PRIMULTI (NCT01960933), and Compare-Acute (NCT01399736). FAME 2 enrolled patients with stable coronary artery disease (CAD), while the other two focused on non-culprit lesions in stabilized patients after acute coronary syndrome. A total of 2400 subjects were recruited from 54 sites world-wide with 1056 randomly assigned to FFR-guided PCI and 1344 to medical therapy. The pre-specified primary outcome was a composite of cardiac death or MI. We included data from extended follow-ups for FAME 2 (up to 5.5 years follow-up) and DANAMI-3-PRIMULTI (up to 4.7 years follow-up). After a median follow-up of 35 months (interquartile range 12-60 months), a reduction in the composite of cardiac death or MI was observed with FFR-guided PCI as compared with medical therapy (hazard ratio 0.72, 95% confidence interval 0.54-0.96; P = 0.02). The difference between groups was driven by MI.

Conclusion

In this IPD meta-analysis of the three available randomized controlled trials to date, FFR-guided PCI resulted in a reduction of the composite of cardiac death or MI compared with medical therapy, which was driven by a decreased risk of MI.

Outcomes in patients treated with ticagrelor or clopidogrel after acute myocardial infarction: experiences from SWEDEHEART registry

AIMS

Ticagrelor reduces ischaemic events and mortality in acute coronary syndrome (ACS) vs. clopidogrel. We wished to study clinical outcomes in a large real-world population post-ACS.

METHODS AND RESULTS

We performed a prospective cohort study in 45 073 ACS patients enrolled into Swedish Web system for Enhancement and Development of Evidence-based care in Heart Disease Evaluated According to Recommended Therapies who were discharged on ticagrelor (N = 11 954) or clopidogrel (N = 33 119) between 1 January 2010 and 31 December 2013. The primary outcome was a composite of all-cause death, re-admission with myocardial infarction (MI) or stroke, secondary outcomes as the individual components of the primary outcome, and re-admission with bleeding. The risk of the primary outcome with ticagrelor vs. clopidogrel was 11.7 vs. 22.3% (adjusted hazard ratio (HR) 0.85 [95% confidence interval: 0.78-0.93]), risk of death 5.8 vs. 12.9% (adjusted HR 0.83 [0.75-0.92]), and risk of MI 6.1 vs. 10.8% (adjusted HR 0.89 [0.78-1.01]) at 24 months. Re-admission with bleeding with ticagrelor vs. clopidogrel occurred in 5.5 vs. 5.2% (adjusted HR 1.20 [1.04-1.40]). In a subset of patients undergoing percutaneous coronary intervention (PCI) on ticagrelor vs. clopidogrel the PCI-related in-hospital bleeding was 3.7 vs. 2.7% (adjusted odds ratio, OR, 1.57 [1.30-1.90]).

CONCLUSION

Ticagrelor vs. clopidogrel post-ACS was associated with a lower risk of death, MI, or stroke, as well as death alone. Risk of bleeding was higher with ticagrelor. These real-world outcomes are consistent with randomized trial results.

The VLDL receptor promotes lipotoxicity and increases mortality in mice following an acute myocardial infarction

Impaired cardiac function is associated with myocardial triglyceride accumulation, but it is not clear how the lipids accumulate or whether this accumulation is detrimental. Here we show that hypoxia/ischemia-induced accumulation of lipids in HL-1 cardiomyocytes and mouse hearts is dependent on expression of the VLDL receptor (VLDLR). Hypoxia-induced VLDLR expression in HL-1 cells was dependent on HIF-1α through its interaction with a hypoxia-responsive element in the Vldlr promoter, and VLDLR promoted the endocytosis of lipoproteins. Furthermore, VLDLR expression was higher in ischemic compared with nonischemic left ventricles from human hearts and was correlated with the total lipid droplet area in the cardiomyocytes. Importantly, Vldlr-/- mice showed improved survival and decreased infarct area following an induced myocardial infarction. ER stress, which leads to apoptosis, is known to be involved in ischemic heart disease. We found that ischemia-induced ER stress and apoptosis in mouse hearts were reduced in Vldlr-/- mice and in mice treated with antibodies specific for VLDLR. These findings suggest that VLDLR-induced lipid accumulation in the ischemic heart worsens survival by increasing ER stress and apoptosis.

Novel rat model reveals important roles of β-adrenoreceptors in stress-induced cardiomyopathy

BACKGROUND

Stress-induced cardiomyopathy (SIC), also known as Takotsubo cardiomyopathy, is an acute cardiac syndrome with substantial morbidity and mortality. The unique hallmark of SIC is extensive ventricular akinesia involving apical segments with preserved function in basal segments. Adrenergic overstimulation plays an important role in initiating SIC but the pathophysiological pathways and receptors involved are unknown.

METHODS

Sprague Dawley rats (~300 g) were injected with a single dose of the β-adrenergic agonist isoprenaline (ISO, i.p.) and echocardiography was used to study cardiac function. The akinetic part of the left ventricle was biopsied in six SIC patients. Amount of intracellular lipid and glycogen as well as degree of permanent cardiac damage were assessed by histology.

RESULTS

In rats, ISO at doses ≥ 50 mg/kg induced severe SIC-like regional akinesia that completely resolved within seven days. Intracellular lipid content was higher in akinetic, but not in normokinetic myocardium in both SIC patients and rats. β2-receptor blockade or Gi-pathway inhibition was associated with less widespread akinesia and low lipid accumulation but significantly increased acute mortality.

CONCLUSIONS

We provide a novel rat model of SIC that supports the hypothesis of circulating catecholamines as initiators of SIC. We propose that the β-adrenoreceptor pathway is important in the setting of severe catecholamine overstimulation and that perturbations of cardiac metabolism occur in SIC.

Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes

OBJECTIVES

The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS).

BACKGROUND

Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization.

METHODS

The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year.

RESULTS

Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04).

CONCLUSIONS

Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year.

Chronic total occlusions in Sweden--a report from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

INTRODUCTION

Evidence for the current guidelines for the treatment of patients with chronic total occlusions (CTO) in coronary arteries is limited. In this study we identified all CTO patients registered in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) and studied the prevalence, patient characteristics and treatment decisions for CTO in Sweden.

METHODS AND RESULTS

Between January 2005 and January 2012, 276,931 procedures (coronary angiography or percutaneous coronary intervention) were performed in 215,836 patients registered in SCAAR. We identified all patients who had 100% luminal diameter stenosis known or assumed to be ≥ 3 months old. After exclusion of patients with previous coronary artery bypass graft (CABG) surgery or coronary occlusions due to acute coronary syndrome, we identified 16,818 CTO patients. A CTO was present in 10.9% of all coronary angiographies and in 16.0% of patients with coronary artery disease. The majority of CTO patients were treated conservatively and PCI of CTO accounted for only 5.8% of all PCI procedures. CTO patients with diabetes and multivessel disease were more likely to be referred to CABG.

CONCLUSION

CTO is a common finding in Swedish patients undergoing coronary angiography but the number of CTO procedures in Sweden is low. Patients with CTO are a high-risk subgroup of patients with coronary artery disease. SCAAR has the largest register of CTO patients and therefore may be valuable for studies of clinical importance of CTO and optimal treatment for CTO patients.

Trends in Gender Differences in Cardiac Care and Outcome After Acute Myocardial Infarction in Western Sweden: A Report From the Swedish Web System for Enhancement of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART)

BACKGROUND

Cardiovascular disease is the most common cause of death for both genders. Debates are ongoing as to whether gender-specific differences in clinical course, diagnosis, and management of acute myocardial infarction (MI) exist.

METHODS AND RESULTS

We compared all men and women who were treated for acute MI at cardiac care units in Västra Götaland, Sweden, between January 1995 and October 2014 by obtaining data from the prospective SWEDEHEART (Swedish Web-System for Enhancement of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry. We performed unadjusted and adjusted Cox proportional hazards and logistic regression analyses on complete case data and on imputed data sets. Overall, 48 118 patients (35.4% women) were diagnosed with acute MI. Women as a group had better age-adjusted prognosis than men, but this survival benefit was absent for younger women (aged <60 years) and for women with ST-segment elevation MI. Compared with men, younger women and women with ST-segment elevation MI were more likely to develop prehospital cardiogenic shock (adjusted odds ratio 1.67, 95% CI 1.30 to 2.16, P<0.001 and adjusted odds ratio 1.31, 95% CI 1.16 to 1.48, P<0.001) and were less likely to be prescribed evidence-based treatment at discharge (P<0.001 for β-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, statins, and P2Y12 antagonists). Differences in treatment between the genders did not decrease over the study period (P>0.1 for all treatments).

CONCLUSIONS

Women on average have better adjusted prognosis than men after acute MI; however, younger women and women with ST-segment elevation MI have disproportionately poor prognosis and are less likely to be prescribed evidence-based treatment.

Hyperinsulinemia: effect on cardiac mass/function, angiotensin II receptor expression, and insulin signaling pathways

To investigate the association between hyperinsulinemia and cardiac hypertrophy, we treated rats with insulin for 7 wk and assessed effects on myocardial growth, vascularization, and fibrosis in relation to the expression of angiotensin II receptors (AT-R). We also characterized insulin signaling pathways believed to promote myocyte growth and interact with proliferative responses mediated by G protein-coupled receptors, and we assessed myocardial insulin receptor substrate-1 (IRS-1) and p110 alpha catalytic and p85 regulatory subunits of phospatidylinositol 3 kinase (PI3K), Akt, MEK, ERK1/2, and S6 kinase-1 (S6K1). Left ventricular (LV) geometry and performance were evaluated echocardiographically. Insulin decreased AT1a-R mRNA expression but increased protein levels and increased AT2-R mRNA and protein levels and phosphorylation of IRS-1 (Ser374/Tyr989), MEK1/2 (Ser218/Ser222), ERK1/2 (Thr202/Tyr204), S6K1 (Thr421/Ser424/Thr389), Akt (Thr308/Thr308), and PI3K p110 alpha but not of p85 (Tyr508). Insulin increased LV mass and relative wall thickness and reduced stroke volume and cardiac output. Histochemical examination demonstrated myocyte hypertrophy and increases in interstitial fibrosis. Metoprolol plus insulin prevented the increase in relative wall thickness, decreased fibrosis, increased LV mass, and improved function seen with insulin alone. Thus our data demonstrate that chronic hyperinsulinemia decreases AT1a-to-AT2 ratio and increases MEK-ERK1/2 and S6K1 pathway activity related to hypertrophy. These changes might be crucial for increased cardiovascular growth and fibrosis and signs of impaired LV function.

Cardiac arrest in COVID-19: characteristics and outcomes of in- and out-of-hospital cardiac arrest. A report from the Swedish Registry for Cardiopulmonary Resuscitation

Aim

To study the characteristics and outcome among cardiac arrest cases with COVID-19 and differences between the pre-pandemic and the pandemic period in out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA).

Method and results

We included all patients reported to the Swedish Registry for Cardiopulmonary Resuscitation from 1 January to 20 July 2020. We defined 16 March 2020 as the start of the pandemic. We assessed overall and 30-day mortality using Cox regression and logistic regression, respectively. We studied 1946 cases of OHCA and 1080 cases of IHCA during the entire period. During the pandemic, 88 (10.0%) of OHCAs and 72 (16.1%) of IHCAs had ongoing COVID-19. With regards to OHCA during the pandemic, the odds ratio for 30-day mortality in COVID-19-positive cases, compared with COVID-19-negative cases, was 3.40 [95% confidence interval (CI) 1.31–11.64]; the corresponding hazard ratio was 1.45 (95% CI 1.13–1.85). Adjusted 30-day survival was 4.7% for patients with COVID-19, 9.8% for patients without COVID-19, and 7.6% in the pre-pandemic period. With regards to IHCA during the pandemic, the odds ratio for COVID-19-positive cases, compared with COVID-19-negative cases, was 2.27 (95% CI 1.27–4.24); the corresponding hazard ratio was 1.48 (95% CI 1.09–2.01). Adjusted 30-day survival was 23.1% in COVID-19-positive cases, 39.5% in patients without COVID-19, and 36.4% in the pre-pandemic period.

Conclusion

During the pandemic phase, COVID-19 was involved in at least 10% of all OHCAs and 16% of IHCAs, and, among COVID-19 cases, 30-day mortality was increased 3.4-fold in OHCA and 2.3-fold in IHCA.