Pretreatment with heparin in patients with ST-segment elevation myocardial infarction: a report from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

BACKGROUND

Unfractionated heparin (UFH) is frequently administered before percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI).

AIMS

The aim of the study was to investigate if pretreatment with UFH prior to arrival at the catheterisation laboratory affects coronary artery occlusion, mortality, and in-hospital major bleeding in patients with STEMI undergoing PCI.

METHODS

Patients with a first STEMI event undergoing PCI between 2008 and 2016 were extracted from the Swedish Coronary Angiography and Angioplasty Registry. Risk ratios for UFH pretreatment versus no pretreatment regarding coronary artery occlusion at presentation in the catheterisation laboratory, 30-day mortality, and bleeding were obtained using adjusted Poisson regression models with robust standard errors. Analyses of propensity score (PS)-matched groups were performed to obtain absolute risk differences.

RESULTS

In all, 41,631 patients were included, 16,026 (38%) with and 25,605 (62%) without UFH pretreatment. Adjusted risk ratios were 0.89 (95% confidence interval [CI]: 0.87 to 0.90) for coronary artery occlusion, 0.87 (0.77 to 0.99) for mortality, and 1.01 (0.86 to 1.18) for bleeding. In the PS-matched analyses, the absolute risk differences were -0.087 (-0.074 to -0.099) for coronary artery occlusion, -0.011 (-0.017 to -0.0041) for mortality, and 0 (-0.0052 to 0.0052) for bleeding.

CONCLUSIONS

Pretreatment with UFH was associated with a reduction in coronary artery occlusion among patients with STEMI, with a number needed to treat (NNT) of 12, without increasing the risk of major in-hospital bleeding. Regarding mortality, a reduction was found with UFH pretreatment, with an NNT of 94, but this effect was not robust over all sensitivity analyses and residual confounding cannot be excluded.

Trends in Clinical Practice and Outcomes After Percutaneous Coronary Intervention of Unprotected Left Main Coronary Artery

Background

The use of percutaneous coronary intervention (PCI) to treat unprotected left main coronary artery disease has expanded rapidly in the past decade. We aimed to describe nationwide trends in clinical practice and outcomes after PCI for left main coronary artery disease.

Methods and Results

Patients (n=4085) enrolled in the SCAAR (Swedish Coronary Angiography and Angioplasty Registry) as undergoing PCI for left main coronary artery disease from 2005 to 2017 were included. A count regression model was used to analyze time‐related differences in procedural characteristics. The 3‐year major adverse cardiovascular and cerebrovascular event rate defined as death, myocardial infarction, stroke, and repeat revascularization was calculated with the Kaplan‐Meier estimator and Cox proportional hazard model. The number of annual PCI procedures grew from 121 in 2005 to 589 in 2017 (389%). The increase was greater for men (479%) and individuals with diabetes (500%). Periprocedural complications occurred in 7.9%, decreasing from 10% to 6% during the study period. A major adverse cardiovascular and cerebrovascular event occurred in 35.7% of patients, falling from 45.6% to 23.9% (hazard ratio, 0.56; 95% CI, 0.41–0.78; P=0.001). Radial artery access rose from 21.5% to 74.2% and intracoronary diagnostic procedures from 14.0% to 53.3%. Use of bare‐metal stents and first‐generation drug‐eluting stents fell from 19.0% and 71.9%, respectively, to 0, with use of new‐generation drug‐eluting stents increasing to 95.2%.

Conclusions

Recent changes in clinical practice relating to PCI for left main coronary artery disease are characterized by a 4‐fold rise in procedures conducted, increased use of evidence‐based adjunctive treatment strategies, intracoronary diagnostics, newer stents, and more favorable outcomes.

Transradial versus trans-femoral access site in high-speed rotational atherectomy in Sweden

BACKGROUND

Radial artery is the preferred access site in contemporary percutaneous coronary intervention (PCI). However, limited data exist regarding utilization pattern, safety, and long-term efficacy of transradial artery access (TRA) PCI in heavily calcified lesions using high-speed rotational atherectomy (HSRA).

METHODS

All patients who underwent HSRA-PCI in Sweden between 2005 and 2016 were included. Outcomes were major adverse cardiac events (MACE, including death, myocardial infarction (MI) or target vessel revascularisation (TVR)), in-hospital bleeding and restenosis. Inverse probability of treatment weighting was used to adjust for the non-randomized access site selection.

RESULTS

We included 1479 patients of whom 649 had TRA and 782 transfemoral artery access (TFA) HSRA-PCI. The rate of TRA increased significantly by 18% per year but remained lower in HSRA-PCI (60%) than in the overall PCI population (85%) in 2016. TRA was associated with comparable angiographic success but significantly lower risk for major (adjusted OR 0.16; 95% CI 0.05-0.47) or any in-hospital bleeding (adjusted OR 0.32; 95% CI 0.13-0.78). At one year, the adjusted risk for MACE (HR 0.87; 95% CI 0.67-1.13) and its individual components did not differ between TRA and TFA patients. The risk for restenosis did not significantly differ between TRA and TFA HSRA-PCI treated lesions (adjusted HR 0.92; 95% CI 0.46-1.81).

CONCLUSION

HSRA-PCI by TRA was associated with significantly lower risk for in-hospital bleeding and equivalent long-term efficacy when compared with TFA. Our data support the feasibility and superior safety profile of TRA in HSRA-PCI.

Sealing of Coronary Perforations With a Second-Generation Covered Stent Graft - Results From the PAST-PERF Registry

BACKGROUND

The PAST-PERF registry was initiated to collect data on the PK Papyrus covered stent, a second-generation device for the treatment of coronary artery perforations with enhanced mechanical properties, but with limited available data.

METHODS

Patients treated for coronary artery perforations with the PK Papyrus stent at 14 international centers were retrospectively identified. The primary effectiveness outcome was successful sealing of the perforation. The primary safety outcome was a composite of all-cause mortality, definite or probable stent thrombosis, myocardial infarction and target lesion revascularization.

RESULTS

Among the 94 included patients, 72.3% (68/94) had Ellis type III and cavity spilling perforations. Complete sealing was achieved in 93.6% (n = 88), and no sealing could be achieved in 3.2% (n = 3, including one patient with a geographical miss and one patient in whom the device could not be implanted). Pericardiocentesis was required in 25.0% (n = 23), emergency cardiac surgery was needed in 7.6% (n = 7), acute stent thrombosis was observed in 1.1% (n = 1), and in-hospital mortality occurred in 11.7% (n = 11). The median follow-up duration was 283 (IQR:40;670) days. At 6 and 12 months, the incidence of the primary safety endpoint was 26.6% [95%CI:18.6;37.1] and 32.0% [95%CI:22.8;43.4], mortality 15.0% [95%CI:9.0;24.6] and 19.0% [95%CI:11.3;30.0], and target lesion revascularization 5.5% [95%CI:2.0;14.6] and 7.7% [95%CI:3.1;18.2]. Two definite stent thrombosis occurred, one during the procedure and one on post-procedure day 233.

CONCLUSIONS

The registry demonstrates favorably high rates of successful stent delivery and sealing of coronary perforations using a second-generation covered stent with low target lesion revascularization and stent thrombosis rates.

ANNOTATED TABLE OF CONTENT

The PAST-PERF registry demonstrates favorably high rates of successful stent delivery and sealing of coronary perforations using a second-generation covered stent with low target lesion revascularization and stent thrombosis rates. Specifically, complete sealing was achieved in 93.6% of patients (n = 88/94), and no sealing could be achieved in 3.2% (n = 3, including one patient with a geographical miss and one patient in whom the device could not be implanted). The 12-month mortality was 19.0% [95%CI:11.3;30.0], the rate of target lesion revascularization was 7.7% [95%CI:3.1;18.2], and two definite stent thromboses occurred (one during procedure and one on post-procedure day 233).

Incidence and outcome of myocardial infarction treated with percutaneous coronary intervention during COVID-19 pandemic

Objective

Most reports on the declining incidence of myocardial infarction (MI) during the COVID-19 have either been anecdotal, survey results or geographically limited to areas with lockdowns. We examined the incidence of MI during the COVID-19 pandemic in Sweden, which has remained an open society with a different public health approach fighting COVID-19.

Methods

We assessed the incidence rate (IR) as well as the incidence rate ratios (IRRs) of all MI referred for coronary angiography in Sweden using the nationwide Swedish Coronary Angiography and Angioplasty Registry (SCAAR), during the COVID-19 pandemic in Sweden (1 March 2020–7 May 2020) in relation to the same days 2015–2019.

Results

A total of 2443 MIs were referred for coronary angiography during the COVID-19 pandemic resulting in an IR 36 MIs/day (204 MIs/100 000 per year) compared with 15 213 MIs during the reference period with an IR of 45 MIs/day (254 MIs/100 000 per year) resulting in IRR of 0.80, 95% CI (0.74 to 0.86), p<0.001. Results were consistent in all investigated patient subgroups, indicating no change in patient category seeking cardiac care. Kaplan-Meier event rates for 7-day case fatality were 439 (2.3%) compared with 37 (2.9%) (HR: 0.81, 95% CI (0.58 to 1.13), p=0.21). Time to percutaneous coronary intervention (PCI) was shorter during the pandemic and PCI was equally performed, indicating no change in quality of care during the pandemic.

Conclusion

The COVID-19 pandemic has significantly reduced the incidence of MI referred for invasive treatment strategy. No differences in overall short-term case fatality or quality of care indicators were observed.

Guiding Principles for Chronic Total Occlusion Percutaneous Coronary Intervention

Outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have improved because of advancements in equipment and techniques. With global collaboration and knowledge sharing, we have identified 7 common principles that are widely accepted as best practices for CTO-PCI.  1. Ischemic symptom improvement is the primary indication for CTO-PCI.  2. Dual coronary angiography and in-depth and structured review of the angiogram (and, if available, coronary computed tomography angiography) are key for planning and safely performing CTO-PCI.  3. Use of a microcatheter is essential for optimal guidewire manipulation and exchanges.  4. Antegrade wiring, antegrade dissection and reentry, and the retrograde approach are all complementary and necessary crossing strategies. Antegrade wiring is the most common initial technique, whereas retrograde and antegrade dissection and reentry are often required for more complex CTOs.  5. If the initially selected crossing strategy fails, efficient change to an alternative crossing technique increases the likelihood of eventual PCI success, shortens procedure time, and lowers radiation and contrast use.  6. Specific CTO-PCI expertise and volume and the availability of specialized equipment will increase the likelihood of crossing success and facilitate prevention and management of complications, such as perforation.  7. Meticulous attention to lesion preparation and stenting technique, often requiring intracoronary imaging, is required to ensure optimum stent expansion and minimize the risk of short- and long-term adverse events. These principles have been widely adopted by experienced CTO-PCI operators and centers currently achieving high success and acceptable complication rates. Outcomes are less optimal at less experienced centers, highlighting the need for broader adoption of the aforementioned 7 guiding principles along with the development of additional simple and safe CTO crossing and revascularization strategies through ongoing research, education, and training.

Clinical and angiographic outcomes of bioabsorbable vs. permanent polymer drug-eluting stents in Sweden: a report from the Swedish Coronary and Angioplasty Registry (SCAAR)

Aims

Randomized clinical trials have consistently demonstrated the non-inferiority of bioabsorbable polymer drug-eluting stents (BP-DES) with respect to DES having permanent polymers (PP-DES). To date, the comparative performance of BP- and PP-DES in the real world has not been extensively investigated.

Methods and results

From October 2011 to June 2016, we analysed the outcomes associated with newer generation DES use in Sweden. After stratification according to the type of DES received at the index procedure, a total of 16 504 and 79 106 stents were included in the BP- and PP-DES groups, respectively. The Kaplan–Meier estimates for restenosis at 2 years were 1.2% and 1.4% in BP- and PP-DES groups, respectively. Definite stent thrombosis (ST) was low in both groups (0.5% and 0.7% in BP- and PP-DES groups, respectively). The adjusted hazard ratio (HR) for either restenosis or definite ST did not differ between BP- and PP-DES [adjusted HR 0.95, 95% confidence interval (CI) 0.74–1.21; P = 0.670 and adjusted HR 0.79, 95% CI 0.57–1.09; P = 0.151, respectively]. Similarly, there were no differences in the adjusted risk of all-cause death and myocardial infarction (MI) between the two groups (adjusted HR for all-cause death 1.01, 95% CI 0.82–1.25; P = 0.918 and adjusted HR for MI 1.05, 95% CI 0.93–1.19; P = 0.404).

Conclusion

In a large, nationwide, and unselected cohort of patients, percutaneous coronary intervention with BP-DES implantation was not associated with an incremental clinical benefit over PP-DES use at 2 years follow-up.

Editor’s Choice- Heparin pre-treatment in patients with ST-segment elevation myocardial infarction and the risk of intracoronary thrombus and total vessel occlusion. Insights from the TASTE trial

Background:

Pre-treatment with unfractionated heparin is common in ST-segment elevation myocardial infarction (STEMI) protocols, but the effect on intracoronary thrombus burden is unknown. We studied the effect of heparin pre-treatment on intracoronary thrombus burden and Thrombolysis in Myocardial Infarction (TIMI) flow prior to percutaneous coronary intervention in patients with STEMI.

Methods:

The Thrombus Aspiration in ST-Elevation Myocardial Infarction in Scandinavia (TASTE) trial angiographically assessed intracoronary thrombus burden and TIMI flow, prior to percutaneous coronary intervention, in patients with STEMI. In this observational sub-study, patients pre-treated with heparin were compared with patients not pre-treated with heparin. Primary end points were a visible intracoronary thrombus and total vessel occlusion prior to percutaneous coronary intervention. Secondary end points were in-hospital bleeding, in-hospital stroke and 30-day all-cause mortality.

Results:

Heparin pre-treatment was administered in 2898 out of 7144 patients (41.0%). Patients pre-treated with heparin less often presented with an intracoronary thrombus (61.3% vs. 66.0%, p<0.001) and total vessel occlusion (62.9% vs. 71.6%, p<0.001). After adjustments, heparin pre-treatment was independently associated with a reduced risk of intracoronary thrombus (odds ratio (OR) 0.73, 95% confidence interval (CI)=0.65–0.83) and total vessel occlusion (OR 0.64, 95% CI=0.56–0.73), prior to percutaneous coronary intervention. There were no significant differences in secondary end points of in-hospital bleeding (OR 0.84, 95% CI=0.55–1.27), in-hospital stroke (OR 1.17, 95% CI=0.48–2.82) or 30-day all-cause mortality (hazard ratio 0.88, 95% CI=0.60–1.30).

Conclusions:

Heparin pre-treatment was independently associated with a lower risk of intracoronary thrombus and total vessel occlusion before percutaneous coronary intervention in patients with STEMI, without evident safety concerns, in this large multi-centre observational study.

Mechanical chest compressions in the coronary catheterization laboratory to facilitate coronary intervention and survival in patients requiring prolonged resuscitation efforts

Background

Resuscitation after cardiac arrest (CA) in the catheterization laboratory (cath-lab) using mechanical chest compressions (CC) during simultaneous percutaneous coronary intervention (PCI) is a strong recommendation in the 2015 European Resuscitation Council (ERC) guidelines. This study aimed at re-evaluating survival to hospital discharge and assess long term outcome in this patient population.

Methods

Patients presenting at the cath lab with spontaneous circulation, suffering CA and requiring prolonged mechanical CC during cath lab procedures between 2009 and 2013 were included. Circumstances leading to CA, resuscitation parameters and outcomes were evaluated within this cohort. For comparison, patients needing prolonged manual CC in the cath lab in the pre-mechanical CC era were evaluated. Six-month and one year survival with a mechanical CC treatment strategy from 2004 to 2013 was also evaluated.

Results

Thirty-two patients were included between 2009 and 2013 (24 ST-elevation myocardial infarction (STEMI), 4 non-STEMI, 2 planned PCI, 1 angiogram and 1 intra-aortic counter pulsation balloon pump insertion). Twenty were in cardiogenic shock prior to inclusion. Twenty-five were successfully treated with PCI. Median mechanical CC duration for the total cohort (n = 32) was 34 min (range 5–90), for the 15 patients with circulation discharged from the cath-lab, 15 min (range 5–90), and for the eight discharged alive from hospital, 10 min (range 5–52). Twenty-five percent survived with good neurological outcome at hospital discharge. Ten patients treated with manual CC were included with one survivor.

Discussion

Eighty-seven percent of the patients included in the mechanical CC cohort had their coronary or cardiac intervention performed during mechanical CC with an 80 % success rate. This shows that the use of mechanical CC during an intervention does not seem to impair the interventional result substantially. The survival rate after one year was 87 %.

Conclusions

Among patients suffering CA treated with mechanical CC in the cath-lab, 25 % had a good neurological outcome at hospital discharge compared to 10 % treated with manual CC. Long term survival in patients discharged from hospital is good.

Angiographic characteristics of intermediate stenosis of the left anterior descending artery for determination of lesion significance as identified by fractional flow reserve

Previous studies have shown a poor correlation between angiographic assessment of stenosis grade (%) and its functional assessment by fractional flow reserve (FFR). This study aimed to investigate whether a more comprehensive evaluation of the coronary angiogram may contribute to a better identification of flow-limiting stenoses. Coronary angiograms of 1,350 patients (1,883 lesions) were retrospectively analyzed for stenosis grade (eyeballing, %) and matched with FFR values. Angiography-derived optimal cut-off values and intervals delineating the [90% sensitivity-90% specificity] range were 50.8% [42.5-65.0%] for the left main (LM), 62.2% [50.0-72.5%] for the proximal (prox)/mid left anterior descending (LAD) artery, 66.3% [57.5-77.5%] for the prox/mid right coronary artery (RCA), 70.5% [60.0-80.0%] for the prox left circumflex/first obtuse marginal (LCX/OM1), and 71.4% [62.5-82.5%] for the more distal segments. In patients with intermediate LAD lesions, 5 angiographic parameters were identified as independent predictors of flow limitation: (1) a 30-50% lesion prox to the lesion of interest, (2) lesion length >20 mm, (3) distal take-off of all diagonal branches ≥2 mm diameter, (4) "apical wrap" of LAD, and (5) collaterals to an occluded LCX/RCA. Based on these results, a risk score (P20-DAC2) for prediction of flow limitation in intermediate LAD lesions was derived. In conclusion, a comprehensive evaluation of the coronary angiogram-in which besides stenosis grade also other lesion/vessel characteristics are evaluated-can lead to a more accurate identification of functionally significant coronary stenoses.

Therapeutic hypothermia for the treatment of acute myocardial infarction-combined analysis of the RAPID MI-ICE and the CHILL-MI trials

In the randomized rapid intravascular cooling in myocardial infarction as adjunctive to percutaneous coronary intervention (RAPID MI-ICE) and rapid endovascular catheter core cooling combined with cold saline as an adjunct to percutaneous coronary intervention for the treatment of acute myocardial infarction CHILL-MI studies, hypothermia was rapidly induced in conscious patients with ST-elevation myocardial infarction (STEMI) by a combination of cold saline and endovascular cooling. Twenty patients in RAPID MI-ICE and 120 in CHILL-MI with large STEMIs, scheduled for primary percutaneous coronary intervention (PCI) within <6 hours after symptom onset were randomized to hypothermia induced by rapid infusion of 600-2000 mL cold saline combined with endovascular cooling or standard of care. Hypothermia was initiated before PCI and continued for 1-3 hours after reperfusion aiming at a target temperature of 33°C. The primary endpoint was myocardial infarct size (IS) as a percentage of myocardium at risk (IS/MaR) assessed by cardiac magnetic resonance imaging at 4±2 days. Patients randomized to hypothermia treatment achieved a mean core body temperature of 34.7°C before reperfusion. Although significance was not achieved in CHILL-MI, in the pooled analysis IS/MaR was reduced in the hypothermia group, relative reduction (RR) 15% (40.5, 28.0-57.6 vs. 46.6, 36.8-63.8, p=0.046, median, interquartile range [IQR]). IS/MaR was predominantly reduced in early anterior STEMI (0-4h) in the hypothermia group, RR=31% (40.5, 28.8-51.9 vs. 59.0, 45.0-67.8, p=0.01, median, IQR). There was no mortality in either group. The incidence of heart failure was reduced in the hypothermia group (2 vs. 11, p=0.009). Patients with large MaR (>30% of the left ventricle) exhibited significantly reduced IS/MaR in the hypothermia group (40.5, 27.0-57.6 vs. 55.1, 41.1-64.4, median, IQR; hypothermia n=42 vs. control n=37, p=0.03), while patients with MaR<30% did not show effect of hypothermia (35.8, 28.3-57.5 vs. 38.4, 27.4-59.7, median, IQR; hypothermia n=15 vs. control n=19, p=0.50). The prespecified pooled analysis of RAPID MI-ICE and CHILL-MI indicates a reduction of myocardial IS and reduction in heart failure by 1-3 hours with endovascular cooling in association with primary PCI of acute STEMI predominantly in patients with large area of myocardium at risk. (ClinicalTrials.gov id NCT00417638 and NCT01379261).

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.).

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).

A pooled analysis of the effect of endovascular cooling on infarct size in patients with ST-elevation myocardial infarction

AIMS

Prior evaluations of endovascular cooling during primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) have suggested variability in treatment effect related to core temperature at the time of reperfusion, to infarct location and time from symptom onset to reperfusion. Recent results from a randomised feasibility study suggest rapid induction of hypothermia in primary PCI results in a significant reduction in infarct size (IS).

METHODS AND RESULTS

Outcomes from two randomised trials of hypothermia in primary PCI were pooled to examine IS as a percentage of left ventricular myocardium assessed by SPECT or magnetic resonance imaging. Compared with controls (n=103), hypothermia (n=94) was associated with a significant 24% relative reduction (RR) in IS (10.7±1.3% vs. 14.1±1.6%, mean±SEM, p=0.049). Among hypothermia-treated patients for whom core temperature <35C° was achieved before reperfusion, IS was reduced by 37% (8.8±1.7% vs. 14.1±1.6%, p=0.01), a benefit observed for both anterior (14.9±2.9% vs. 22.2±2.7%, RR 33%; p=0.03) and inferior infarcts (4.5±1.4% vs. 7.7±1.3%, RR 42%; p=0.04).

CONCLUSIONS

In a pooled analysis of randomised trials evaluating adjunctive hypothermia in primary PCI, achievement of core body temperature <35°C before reperfusion may reduce infarct size with a similar efficacy for both anterior and inferior MI.

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.).

Percutaneous Coronary Intervention During Cardiac Arrest and Ongoing Chest Compressions

Prolonged cardiac arrest in the cath lab is associated with very high mortality rates. Use of manual chest compressions have, until recently, been the only rapid response available to circulate the patient in such scenarios. The recent introduction of mechanical chest compression devices offers a new alternative that may perform better than manual chest compressions, especially during a continued interventional procedure.

Quality of cardiopulmonary resuscitation in out-of-hospital cardiac arrest is hampered by interruptions in chest compressions--a nationwide prospective feasibility study

AIM OF THE STUDY

Quality of cardiopulmonary resuscitation (CPR) is a critical determinant of outcome following out-of-hospital cardiac arrest. The aim of our study was to evaluate the quality of CPR provided by emergency medical service providers (Basic Life Support (BLS) capability) and emergency medical service providers assisted by paramedics, nurse anesthetists or physician-manned ambulances (Advanced Life Support (ALS) capability) in a nationwide, unselected cohort of out-of-hospital cardiac arrest cases.

METHODS

We conducted a prospective, observational study of out-of-hospital cardiac arrest with non-traumatic etiology (>18 years of age) occurring from the 1st to the 31st of January 2009 and treated by the primary Danish emergency medical service operator, covering approximately 85% of the population. One hundred and ninety-one cases were eligible for analysis. Follow-up was up to one year or death. Quality of CPR was evaluated using measurements of transthoracic impedance.

RESULTS

The majority of patients were treated by ambulances with ALS capability (54%). Interruptions in CPR related to loading of the patient into the emergency medical service vehicle were substantial, but independent of whether patients were managed by ALS or BLS capable units (222s versus 224s, P = 0.76) as were duration of interruptions during rhythm analysis alone (20s versus 22s, P = 0.33) and defibrillation (24s versus 26s, P = 0.07).

CONCLUSIONS

Nationwide, routine monitoring of transthoracic impedance is feasible. CPR is hampered by extended interruptions, particularly during loading of the patient into the emergency medical service vehicle, rhythm analysis and defibrillation.

Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia (TASTE trial). A multicenter, prospective, randomized, controlled clinical registry trial based on the Swedish angiography and angioplasty registry (SCAAR) platform. Study design and rationale

BACKGROUND

In ST-elevation myocardial infarction (STEMI), distal embolization of thrombus material often precludes restoration of normal coronary artery flow. Small-scaled studies have demonstrated that intracoronary thrombus aspiration improves flow and myocardial perfusion, but only one larger randomized single-center study has suggested a survival benefit. Thrombus aspiration is widely used in clinical practice and is recommended by international guidelines despite limited evidence.

METHODS/DESIGN

The Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia is a multicenter, prospective, randomized, controlled, clinical open-label trial based on the Swedish angiography and angioplasty registry (SCAAR) platform with blinded evaluation of end points. A total of 5,000 patients with STEMI undergoing primary percutaneous coronary intervention (PCI) will randomly be assigned either to conventional PCI or to thrombus aspiration followed by PCI. SCAAR will be used as the platform for randomization, allowing a broad population of all-comers in the registry network to be enrolled. All follow-up will also be done in SCAAR and other national registries. The primary end point is time to all-cause death at 30 days.

DISCUSSION

The Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia trial is the largest trial to date to evaluate the effect of thrombus aspiration on death following PCI in patients with STEMI. We propose the term randomized clinical registry trial to describe the novel entity of using an online national registry as platform for case records, randomization, and follow-up.

Treatment with the C5a receptor antagonist ADC-1004 reduces myocardial infarction in a porcine ischemia-reperfusion model

BACKGROUND

Polymorphonuclear neutrophils, stimulated by the activated complement factor C5a, have been implicated in cardiac ischemia/reperfusion injury. ADC-1004 is a competitive C5a receptor antagonist that has been shown to inhibit complement related neutrophil activation. ADC-1004 shields the neutrophils from C5a activation before they enter the reperfused area, which could be a mechanistic advantage compared to previous C5a directed reperfusion therapies. We investigated if treatment with ADC-1004, according to a clinically applicable protocol, would reduce infarct size and microvascular obstruction in a large animal myocardial infarct model.

METHODS

In anesthetized pigs (42-53 kg), a percutaneous coronary intervention balloon was inflated in the left anterior descending artery for 40 minutes, followed by 4 hours of reperfusion. Twenty minutes after balloon inflation the pigs were randomized to an intravenous bolus administration of ADC-1004 (175 mg, n = 8) or saline (9 mg/ml, n = 8). Area at risk (AAR) was evaluated by ex vivo SPECT. Infarct size and microvascular obstruction were evaluated by ex vivo MRI. The observers were blinded to the treatment at randomization and analysis.

RESULTS

ADC-1004 treatment reduced infarct size by 21% (ADC-1004: 58.3 ± 3.4 vs control: 74.1 ± 2.9%AAR, p = 0.007). Microvascular obstruction was similar between the groups (ADC-1004: 2.2 ± 1.2 vs control: 5.3 ± 2.5%AAR, p = 0.23). The mean plasma concentration of ADC-1004 was 83 ± 8 nM at sacrifice. There were no significant differences between the groups with respect to heart rate, mean arterial pressure, cardiac output and blood-gas data.

CONCLUSIONS

ADC-1004 treatment reduces myocardial ischemia-reperfusion injury and represents a novel treatment strategy of myocardial infarct with potential clinical applicability.

Rationale and design of EXPLORE: a randomized, prospective, multicenter trial investigating the impact of recanalization of a chronic total occlusion on left ventricular function in patients after primary percutaneous coronary intervention for acute ST-elevation myocardial infarction

Background

In the setting of primary percutaneous coronary intervention, patients with a chronic total occlusion in a non-infarct related artery were recently identified as a high-risk subgroup. It is unclear whether ST-elevation myocardial infarction patients with a chronic total occlusion in a non-infarct related artery should undergo additional percutaneous coronary intervention of the chronic total occlusion on top of optimal medical therapy shortly after primary percutaneous coronary intervention. Possible beneficial effects include reduction in adverse left ventricular remodeling and preservation of global left ventricular function and improved clinical outcome during future coronary events.

Methods/Design

The Evaluating Xience V and left ventricular function in Percutaneous coronary intervention on occLusiOns afteR ST-Elevation myocardial infarction (EXPLORE) trial is a randomized, prospective, multicenter, two-arm trial with blinded evaluation of endpoints. Three hundred patients after primary percutaneous coronary intervention for ST-elevation myocardial infarction with a chronic total occlusion in a non-infarct related artery are randomized to either elective percutaneous coronary intervention of the chronic total occlusion within seven days or standard medical treatment. When assigned to the invasive arm, an everolimus-eluting coronary stent is used. Primary endpoints are left ventricular ejection fraction and left ventricular end-diastolic volume assessed by cardiac Magnetic Resonance Imaging at four months. Clinical follow-up will continue until five years.

Discussion

The ongoing EXPLORE trial is the first randomized clinical trial powered to investigate whether recanalization of a chronic total occlusion in a non-infarct related artery after primary percutaneous coronary intervention for ST-elevation myocardial infarction results in a better preserved residual left ventricular ejection fraction, reduced end-diastolic volume and enhanced clinical outcome.

Trial registration

trialregister.nl NTR1108.

A pilot study of rapid cooling by cold saline and endovascular cooling before reperfusion in patients with ST-elevation myocardial infarction

BACKGROUND

Experimental studies have shown that induction of hypothermia before reperfusion of acute coronary occlusion reduces infarct size. Previous clinical studies, however, have not been able to show this effect, which is believed to be mainly because therapeutic temperature was not reached before reperfusion in the majority of the patients. We aimed to evaluate the safety and feasibility of rapidly induced hypothermia by infusion of cold saline and endovascular cooling catheter before reperfusion in patients with acute myocardial infarction.

METHODS AND RESULTS

Twenty patients with acute myocardial infarction scheduled to undergo primary percutaneous coronary intervention were enrolled in this prospective, randomized study. After 4 ± 2 days, myocardium at risk and infarct size were assessed by cardiac magnetic resonance using T2-weighted imaging and late gadolinium enhancement imaging, respectively. A core body temperature of <35°C (34.7 ± 0.3°C) was achieved before reperfusion without significant delay in door-to-balloon time (43 ± 7 minutes versus 40 ± 6 minutes, hypothermia versus control, P=0.12). Despite similar duration of ischemia (174 ± 51 minutes versus 174 ± 62 minutes, hypothermia versus control, P=1.00), infarct size normalized to myocardium at risk was reduced by 38% in the hypothermia group compared with the control group (29.8 ± 12.6% versus 48.0 ± 21.6%, P=0.041). This was supported by a significant decrease in both peak and cumulative release of Troponin T in the hypothermia group (P=0.01 and P=0.03, respectively).

CONCLUSIONS

The protocol demonstrates the ability to reach a core body temperature of <35°C before reperfusion in all patients without delaying primary percutaneous coronary intervention and that combination hypothermia as an adjunct therapy in acute myocardial infarction may reduce infarct size at 3 days as measured by MRI.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00417638.

Changes in cardiac pumping efficiency and intra-thoracic organ volume during negative pressure wound therapy of sternotomy wounds, assessment using magnetic resonance imaging

Knowledge on the effects of negative pressure wound therapy (NPWT) on the intra-thoracic organs is limited. The present study was performed to investigate the effects of NPWT on the volume of the intra-thoracic organs, using magnetic resonance imaging (MRI), in a porcine sternotomy wound model. Six pigs underwent median sternotomy followed by NPWT at -75, -125 and -175 mmHg. Six pigs were not sternotomised. MR images covering the thorax and heart were acquired. The volumes of the thoracic cavity, lungs, wound fluid and heart were then determined. The volumes of the thoracic cavity and intra-thoracic organs increased after sternotomy and decreased upon NPWT application. The total heart volume variation, which is inversely related to cardiac pumping efficiency, was higher after sternotomy and decreased during NPWT. NPWT did not result in the evacuation of wound fluid from the bottom of the wound. NPWT largely closes and restores the thoracic cavity. Cardiac pumping efficiency returns to pre-sternotomy levels during NPWT. This may contribute to the clinical benefits of NPWT over open-chest care, including the stabilizing effects and the reduced need for mechanical ventilation.

Changes in cardiac pumping efficiency and intra-thoracic organ volume during negative pressure wound therapy of sternotomy wounds, assessment using magnetic resonance imaging

Knowledge on the effects of negative pressure wound therapy (NPWT) on the intra-thoracic organs is limited. The present study was performed to investigate the effects of NPWT on the volume of the intra-thoracic organs, using magnetic resonance imaging (MRI), in a porcine sternotomy wound model. Six pigs underwent median sternotomy followed by NPWT at -75, -125 and -175 mmHg. Six pigs were not sternotomised. MR images covering the thorax and heart were acquired. The volumes of the thoracic cavity, lungs, wound fluid and heart were then determined. The volumes of the thoracic cavity and intra-thoracic organs increased after sternotomy and decreased upon NPWT application. The total heart volume variation, which is a measure of cardiac pumping efficiency, was higher after sternotomy and decreased during NPWT. NPWT did not result in the evacuation of wound fluid from the bottom of the wound. NPWT largely closes and restores the thoracic cavity. Cardiac pumping efficiency returns to pre-sternotomy levels during NPWT. This may contribute to the clinical benefits of NPWT over open-chest care, including the stabilizing effects and the reduced need for mechanical ventilation.

Apyrase treatment of myocardial infarction according to a clinically applicable protocol fails to reduce myocardial injury in a porcine model

Background

Ectonucleotidase dependent adenosine generation has been implicated in preconditioning related cardioprotection against ischemia-reperfusion injury, and treatment with a soluble ectonucleotidase has been shown to reduce myocardial infarct size (IS) when applied prior to induction of ischemia. However, ectonucleotidase treatment according to a clinically applicable protocol, with administration only after induction of ischemia, has not previously been evaluated. We therefore investigated if treatment with the ectonucleotidase apyrase, according to a clinically applicable protocol, would reduce IS and microvascular obstruction (MO) in a large animal model.

Methods

A percutaneous coronary intervention balloon was inflated in the left anterior descending artery for 40 min, in 16 anesthetized pigs (40-50 kg). The pigs were randomized to 40 min of 1 ml/min intracoronary infusion of apyrase (10 U/ml, n = 8) or saline (0.9 mg/ml, n = 8), twenty minutes after balloon inflation. Area at risk (AAR) was evaluated by ex vivo SPECT. IS and MO were evaluated by ex vivo MRI.

Results

No differences were observed between the apyrase group and saline group with respect to IS/AAR (75.7 ± 4.2% vs 69.4 ± 5.0%, p = NS) or MO (10.7 ± 4.8% vs 11.4 ± 4.8%, p = NS), but apyrase prolonged the post-ischemic reactive hyperemia.

Conclusion

Apyrase treatment according to a clinically applicable protocol, with administration of apyrase after induction of ischemia, does not reduce myocardial infarct size or microvascular obstruction.

The porcine retinal vasculature accessed using an endovascular approach: a new experimental model for retinal ischemia

PURPOSE

The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia.

METHODS

Six experiments were performed using 100-kg pigs. The external carotid system was catheterized using a fluoroscopy-monitored, transfemoral, endovascular approach. Transient and permanent vascular occlusions were performed using an angioplasty balloon catheter or a liquid embolic agent that was administered via an injection-catheter.

RESULTS

A technique for transfemoral catheterization of arteries supplying the retina was established. The ophthalmic artery was demonstrated to give rise to the main ciliary artery from which the retinal artery branched as a single artery or as several arteries. A balloon-catheter could be introduced into the ophthalmic artery but not into the main ciliary artery. An injection-catheter could, in all experiments, be introduced into the main ciliary artery and, in some experiments, into the retinal artery. Occlusion of the ophthalmic artery, over the branching of the main ciliary artery, caused incomplete ischemia, presumably because of collaterals feeding the distal parts of the vasculature. Multifocal ERG (mfERG) recordings showed decreased amplitudes and increased implicit times, indicating retinal ischemia. Occlusion of the ciliary and retinal arteries caused complete ischemia, as shown by complete flattening of the mfERG recordings and, by indirect ophthalmoscopy, blanching of the retinal arteries and a pale retina,

CONCLUSIONS

The authors show for the first time that the ophthalmic and retinal artery can be catheterized using a transfemoral endovascular approach. This technique may be useful to produce clear-cut experimental retinal ischemia.

Can pulsed ultrasound increase tissue damage during ischemia? A study of the effects of ultrasound on infarcted and non-infarcted myocardium in anesthetized pigs

BACKGROUND

The same mechanisms by which ultrasound enhances thrombolysis are described in connection with non-beneficial effects of ultrasound. The present safety study was therefore designed to explore effects of beneficial ultrasound characteristics on the infarcted and non-infarcted myocardium.

METHODS

In an open chest porcine model (n = 17), myocardial infarction was induced by ligating a coronary diagonal branch. Pulsed ultrasound of frequency 1 MHz and intensity 0.1 W/cm2 (ISATA) was applied during one hour to both infarcted and non-infarcted myocardial tissue. These ultrasound characteristics are similar to those used in studies of ultrasound enhanced thrombolysis. Using blinded assessment technique, myocardial damage was rated according to histopathological criteria.

RESULTS

Infarcted myocardium exhibited a significant increase in damage score compared to non-infarcted myocardium: 6.2 +/- 2.0 vs. 4.3 +/- 1.5 (mean +/- standard deviation), (p = 0.004). In the infarcted myocardium, ultrasound exposure yielded a further significant increase of damage scores: 8.1 +/- 1.7 vs. 6.2 +/- 2.0 (p = 0.027).

CONCLUSION

Our results suggest an instantaneous additive effect on the ischemic damage in myocardial tissue when exposed to ultrasound of stated characteristics. The ultimate damage degree remains to be clarified.

Aortic valve replacement in patients older than 85 years: outcomes and the effect on their quality of life

PURPOSE

The aim of this study was to investigate the outcome of aortic valve replacement (AVR) and the effect on quality of life in patients aged over 85 who had symptomatic aortic stenosis.

METHODS

We performed a retrospective analysis of 21 patients, aged 85-91 years (mean age 86.5), who underwent AVR, 10 of whom underwent concomitant coronary artery bypass grafting (CABG) between 1989 and 1995. All patients were categorized as New York Heart Association (NYHA) functional class III and IV. A questionnaire was used to evaluate heart symptoms and quality of life among the 13 patients who were alive at follow-up (9-83 months).

RESULTS

Eighteen patients were categorized as NYHA functional class I and II for 1 year (9 months for one patient) after AVR. Three patients, all undergoing concomitant CABG, died early. The overall 1-, 2- and 3-year actuarial survival rate was 85%, 64% and 53% (among the patients undergoing only AVR the figures were 100%, 100% and 85%). Follow-up questionnaire results showed an improvement in the patients' symptoms of heart disease, dyspnea (P = 0.017) and angina (P = 0.03). An improvement in the patients' physical functioning (P = 0.025), satisfaction with physical ability (P = 0.005), sleep (P = 0.025), health status (P = 0.025) and perception of general health (P = 0.005) was also observed.

CONCLUSIONS

Our results show that AVR can be performed on patients > or = 85 years of age or older, with an improvement in heart symptoms and quality of life.