A randomised trial of selective intracoronary hypothermia during primary PCI.

BACKGROUND: While experimental data suggest that selective intracoronary hypothermia decreases infarct size, studies in patients with ST-elevation myocardial infarction (STEMI) are lacking. AIMS: We investigated the efficacy of selective intracoronary hypothermia during primary percutaneous coronary intervention (PCI) to decrease infarct size in patients with STEMI. METHODS: In this multicentre randomised controlled trial, 200 patients with large anterior wall STEMI were randomised 1:1 to selective intracoronary hypothermia during primary PCI or primary PCI alone. Using an over-the-wire balloon catheter for infusion of cold saline and a pressure-temperature wire to monitor the intracoronary temperature, the anterior myocardium distal to the occlusion was selectively cooled to 30-33°C for 7-10 minutes before reperfusion (occlusion phase), immediately followed by 10 minutes of cooling after reperfusion (reperfusion phase). The primary endpoint was infarct size as a percentage of left ventricular mass on cardiovascular magnetic resonance imaging after 3 months. RESULTS: Selective intracoronary hypothermia was performed in 94/100 patients randomised to cooling. Distal coronary temperature decreased by 6°C within 43 seconds (interquartile range [IQR] 18-113). The median duration of the occlusion phase and reperfusion phase were 8.2 minutes (IQR 7.2-9.0) and 9.1 minutes (IQR 8.2-10.0), respectively. The infarct size at 3 months was 23.1±12.5% in the selective intracoronary hypothermia group and 21.6±12.2% in the primary PCI alone group (p=0.43). The left ventricular ejection fraction at 3 months in each group were 49.1±10.2% and 50.1±10.4%, respectively (p=0.53). CONCLUSIONS: Selective intracoronary hypothermia during primary PCI in patients with anterior wall STEMI was feasible and safe but did not decrease infarct size compared with standard primary PCI. (ClinicalTrials.gov: NCT03447834).

Fluid-filled versus sensor-tipped pressure guidewires for FFR and Pd/Pa measurement; PW-COMPARE study.

BACKGROUND: Fluid-filled pressure guidewires are unaffected by the previously inevitable hydrostatic pressure gradient (HPG). This study aimed to compare simultaneous pressure measurements with fluid-filled and sensor-tipped pressure guidewires. METHODS: Fifty patients underwent fractional flow reserve (FFR) and Pd/Pa measurement with a fluid-filled and a sensor-tipped pressure guidewire simultaneously. To assess maneuverability, patients were randomized with respect to which pressure guidewire was used to cross the lesion first. Lateral fluoroscopy was used to estimate height difference between catheter tip and distal wire position (and thus HPG). Agreement between pressure measurements was studied. RESULTS: Measurements were performed in LM (4% (n = 2)), LAD (44% (n = 22)), LCX (26% (n = 13)), and RCA (26% (n = 13)). Simultaneous pressure measurements showed excellent agreement (mean FFR difference - 0.01 ± 0.03 (r = 0.959, p < 0.001), mean Pd/Pa difference - 0.01 ± 0.04 (r = 0.929, p < 0.001)). FFR was ≤0.80 in 42.6% (n = 20) with fluid-filled FFR measurements versus 46.8% (n = 22) by sensor-tipped FFR measurements. Mean height difference was 15 ± 34 mm, and strongly dependent on the coronary artery (LAD 45 ± 10 mm, LCX -23 ± 16 mm, RCA -13 ± 17 mm). There was a strong correlation between height difference and difference in pressure ratios between sensor-tipped and fluid-filled pressure guidewires (FFR r = -0.850, p < 0.001; Pd/Par = -0.641, p < 0.001). Largest FFR differences were present in the LAD (-0.04 ± 0.02). After HPG correction, mean difference between HPG-corrected sensor-tipped FFR and fluid-filled FFR was 0.00 ± 0.02, mean Pd/Pa difference was 0.01 ± 0.03. CONCLUSIONS: This study shows excellent overall correlation between FFR and Pd/Pa measurements with both pressure guidewires. Differences measured with fluid-filled and sensor-tipped pressure guidewires are vessel-specific and attributable to hydrostatic pressure gradients (NCT04802681).

Results of systematic patient outcome monitoring: Does post-dilatation during angiography-guided percutaneous coronary intervention improve clinical outcomes?

OBJECTIVES: This study evaluates clinical outcomes after implementing a liberal post-dilatation strategy during PCI. BACKGROUND: Post-dilatation after percutaneous coronary intervention (PCI) is performed to achieve optimal stent expansion and reduce complications. However, its prognostic effects are unclear and conflicting. METHODS: This study is a pre-post-intervention analysis of two cohorts, before (2015-2017) and after (2018-2020) implementation of a liberal post-dilatation strategy. The primary end point consisted of major adverse cardiovascular events (MACE) at 30 days. Secondary end points consisted of the individual components of the primary end point as well as 1 year mortality and target vessel revascularization. RESULTS: A total of 10,153 patients were included: 5,383 in the pre-cohort and 4,770 in the post-cohort. The 30-day MACE was 5.00% in the pre-cohort and 4.09% in the post-cohort (p = 0.008; OR 0.75 (CI 0.61-0.93)). There was a significant difference between the pre- and post-cohort in 30-day mortality, respectively, 2.91% and 2.25% (p = .01; OR 0.70 (CI 0.53-0.93)), and MI at 30 days, 1.17% versus 0.59% (p = .003; OR 0.49 (CI 0.31-0.78)). At 1 year, there was a significant difference in mortality between the pre-cohort, 5.84%, and post-cohort, 5.19% (p = .02; OR 0.79 (CI 0.66-0.96)). CONCLUSIONS: A liberal post-dilatation strategy after PCI was associated with a significant decrease in 30-day MACE, 30-day MI, 30-day mortality, and 1-year mortality. Future studies are warranted to validate the causality between post-dilatation and improvement of clinical outcomes.

Bifurcation PCI with a hybrid strategy with drug- eluting balloons versus a stepwise provisional two- stent strategy: Rationale and design of the hybrid DEB study.

The optimal treatment strategy for coronary bifurcation lesions by percutaneous coronary intervention (PCI) is complex and remains a subject of debate. Current guidelines advise a stepwise provisional approach with optional two-stent strategy. However, a two-stent strategy, both upfront and stepwise provisional, is technically demanding. Therefore, there is increasing interest in the use of drug-eluting balloons (DEB) in bifurcation lesions, mainly after a provisional approach with unsatisfactory result of the side branch. Some small pilot studies already showed that the use of DEB in bifurcation lesions is safe and feasible. However, a randomized comparison of this hybrid DEB strategy with a two-stent strategy is currently lacking. TRIAL DESIGN: The Hybrid DEB study is a prospective, multicenter, randomized controlled trial investigating noninferiority of a hybrid DEB approach, using a combination of a drug-eluting stent (DES) in the main vessel and DEB in the side branch, compared to stepwise provisional two-stent strategy in patients with true bifurcation lesions. A total of 500 patients with de novo true coronary bifurcation lesions, treated with a stepwise provisional approach and an unsatisfactory result of the side branch after main vessel stenting (≥ 70% stenosis and/or < thrombolysis in myocardial infarction III flow), will be randomized in a 1:1 ratio to receive either treatment with a DEB or with a DES in the side branch. The primary endpoint is a composite endpoint of the occurrence of all-cause death, periprocedural or spontaneous myocardial infarction and/or target vessel revascularization at the anticipated median 2-year follow-up. CONCLUSION: The Hybrid DEB study will compare in a multicenter, randomized fashion a hybrid DEB approach with a stepwise provisional two-stent strategy in patients with true bifurcation lesions. TRIAL REGISTRATION: ClinicalTrials.gov no. NCT05731687.

Direct admission versus interhospital transfer for revascularisation in non-ST-segment elevation myocardial infarction.

BACKGROUND: The differences in outcomes and process parameters for NSTEMI patients who are directly admitted to an intervention centre and patients who are first admitted to a general centre are largely unknown. HYPOTHESIS: There are differences in process indicators, but not for clinical outcomes, for NSTEMI who are directly admitted to an intervention centre and patients who are first admitted to a general centre. METHODS: We aim to compare process indicators, costs and clinical outcomes of non-ST-segment elevation myocardial infarction (NSTEMI) patients stratified by center of first presentation and revascularisation strategy. Hospital claim data from patients admitted with a NSTEMI between 2017 and 2019 were used for this study. Included patients were stratified by center of admission (intervention vs. general center) and subdivided by revascularisation strategy (PCI, CABG, or no revascularisation [noRevasc]). The primary outcome was length of hospital stay. Secondary outcomes included: duration between admission and diagnostic angiography and revascularisation, number of intracoronary procedures, clinical outcomes at 30 days (MACE: all-cause mortality, recurrent myocardial infarction and cardiac readmission) and total costs (accumulation of costs for hospital claims and interhospital ambulance rides). RESULTS: A total of 9641 NSTEMI events (9167 unique patients) were analyzed of which 5399 patients (56%) were admitted at an intervention center and 4242 patients to a general center. Duration of hospitalization was significantly shorter at direct presentation at an intervention centre for all study groups (5 days [2-11] vs. 7 days [4-12], p < 0.001). For PCI, direct presentation at an intervention center yielded shorter time to diagnostic angiography (1 day [0-2] vs. 1 day [1-2], p < 0.01) and revascularisation (1 day [0-3] vs. 4 days [1-7], p < 0.001) and less intracoronary procedures per patient (2 [1-2] vs. 2 [2-2], p < 0.001). For CABG, time to revascularisation was shorter (8 days [5-12] vs. 10 days [7-14], p < 0.001). Total costs were significantly lower in case of direct presentation in an intervention center for all treatment groups €10.211 (8750-18.192) versus €13.741 (11.588-19.381), p < 0.001) while MACE was similar 11.8% versus 12.4%, p = 0.344). CONCLUSION: NSTEMI patients who were directly presented to an intervention center account for shorter duration of hospitalization, less time to revascularisation, less interhospital transfers, less intracoronary procedures and lower costs compared to patients who present at a general center.

Changes in absolute flow, myocardial resistance and FFR after chronic total occlusion percutaneous coronary intervention.

BACKGROUND: Randomised studies of percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) have shown inconsistent outcomes, suggesting incomplete understanding of this cohort and their coronary physiology. To address this shortcoming, we designed a prospective observational study to measure the recovery of absolute coronary blood flow following successful CTO PCI Aims: We sought to identify patient and procedural characteristics associated with a favourable physiological outcome after CTO PCI. METHODS: Consecutive patients with a CTO subtending viable myocardium underwent PCI utilising contemporary techniques and the hybrid algorithm. Immediately after PCI, and at 3-month follow-up, physiological measurements were performed utilising continuous thermodilution. RESULTS: A total of 81 patients were included with a mean age of 63.6±8.9 years, and 66 (81.5%) were male. Physiological measurements of absolute coronary blood flow in the CTO vessel increased by 30% (p<0.001) and microvascular resistance reduced by 16% (p<0.001) from immediately post-CTO PCI to follow-up assessment. Fractional flow reserve increased by 0.02 (p=0.015) in the same period. Prior coronary artery bypass graft (CABG) and a higher estimated glomerular filtration rate (eGFR) were associated with a larger change in absolute flow. An extraplaque strategy was associated with a smaller change in absolute flow. CONCLUSIONS: Post-CTO PCI, there is a continued augmentation in absolute coronary blood flow and reduction in microvascular resistance from baseline to follow-up at 3 months. Prior CABG and a higher baseline eGFR were predictors of a larger change in absolute coronary flow, whilst an extraplaque final wire path strategy predicted a smaller change. Lastly, the patient characteristics and comorbidities had a larger influence than procedural factors on the observed change in absolute flow.

Changes in coronary collateral function after successful chronic total occlusion percutaneous coronary intervention.

BACKGROUND: Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) incorporates wire escalation and dissection/re-entry recanalisation strategies. AIMS: The purpose of the study was to investigate changes in collateral function after CTO PCI and to identify whether the mode of successful recanalisation influences collateral function regression. METHODS: Patients scheduled for elective CTO PCI with evidence of viability in the CTO territory by noninvasive imaging were included in this study. After successful CTO PCI, the aortic pressure (Pa) and distal coronary artery wedge pressure (Pw) during balloon occlusion were measured, both in a resting state and during infusion of intravenous adenosine, allowing the calculation of the pressure-derived collateral pressure index at rest and hyperaemia (CPIrest and the collateral fractional flow reserve [FFRcoll], respectively). Measurements were repeated 3 months later during angiographic follow-up. RESULTS: Eighty-one patients had physiological measurements at baseline and follow-up. In the final cohort the mean age was 64 years and 82% were male. The mean maximal stent diameter and total stent length were 3.2±0.5 mm and 68±31 mm, respectively. Successful strategies were antegrade wiring (64.2%), antegrade dissection re-entry (8.6%), and retrograde dissection re-entry (27.1%). Between the index procedure and follow-up, wedge pressure decreased from 34±11 mmHg to 21±8.5 mmHg (p<0.01), respectively. FFRcoll changed from 0.34±0.11 to 0.19±0.09 (p<0.01) at follow-up and CPIrest from 0.40±0.14 to 0.17±0.09 (p<0.01). Absolute maximum collateral flow decreased from 55±32 ml/min directly after PCI to 38±24 ml/min (p<0.01). There was no relation between the recanalisation technique and changes in FFRcoll. CONCLUSIONS: There was a significant reduction in collateral flow over time, independent of the recanalisation technique.

Right ventricular hematoma: A rare but potentially fatal complication of percutaneous coronary artery intervention.

Right ventricular hematoma secondary to coronary artery perforation during the percutaneous coronary intervention (PCI) is a rare complication. Nevertheless, with the growth of complex PCIs, including chronic total occlusion procedures, this complication may increase in frequency. We describe three cases of subepicardial right ventricular hematoma after complex right coronary artery PCI with different outcomes. Two cases were successfully managed with medication only. One case was managed with medication and pericardial drainage, unfortunately with a fatal outcome. All cases emphasize the need for awareness concerning this complication, which warrants prompt diagnosis and adequate therapy.

Prehospital risk assessment in patients suspected of non-ST-segment elevation acute coronary syndrome: a systematic review and meta-analysis.

OBJECTIVE: To review, inventory and compare available diagnostic tools and investigate which tool has the best performance for prehospital risk assessment in patients suspected of non-ST-segment elevation acute coronary syndrome (NSTE-ACS). METHODS: Systematic review and meta-analysis. Medline and Embase were searched up till 1 April 2021. Prospective studies with patients, suspected of NSTE-ACS, presenting in the primary care setting or by emergency medical services (EMS) were included. The most important exclusion criteria were studies including only patients with ST-elevation myocardial infarction and studies before 1995, the pretroponin era. The primary end point was the final hospital discharge diagnosis of NSTE-ACS or major adverse cardiac events (MACE) within 6 weeks. Risk of bias was evaluated by the Quality Assessment of Diagnostic Accuracy Studies Criteria. MAIN OUTCOME AND MEASURES: Sensitivity, specificity and likelihood ratio of findings for risk stratification in patients suspected of NSTE-ACS. RESULTS: In total, 15 prospective studies were included; these studies reflected in total 26 083 patients. No specific variables related to symptoms, physical examination or risk factors were useful in risk stratification for NSTE-ACS diagnosis. The most useful electrocardiographic finding was ST-segment depression (LR+3.85 (95% CI 2.58 to 5.76)). Point-of-care troponin was found to be a strong predictor for NSTE-ACS in primary care (LR+14.16 (95% CI 4.28 to 46.90) and EMS setting (LR+6.16 (95% CI 5.02 to 7.57)). Combined risk scores were the best for risk assessment in an NSTE-ACS. From the combined risk scores that can be used immediately in a prehospital setting, the PreHEART score, a validated combined risk score for prehospital use, derived from the HEART score (History, ECG, Age, Risk factors, Troponin), was most useful for risk stratification in patients with NSTE-ACS (LR+8.19 (95% CI 5.47 to 12.26)) and for identifying patients without ACS (LR-0.05 (95% CI 0.02 to 0.15)). DISCUSSION: Important study limitations were verification bias and heterogeneity between studies. In the prehospital setting, several diagnostic tools have been reported which could improve risk stratification, triage and early treatment in patients suspected for NSTE-ACS. On-site assessment of troponin and combined risk scores derived from the HEART score are strong predictors. These results support further studies to investigate the impact of these new tools on logistics and clinical outcome. FUNDING: This study is funded by ZonMw, the Dutch Organisation for Health Research and Development. TRIAL REGISTRATION NUMBER: This meta-analysis was published for registration in PROSPERO prior to starting (CRD York, CRD42021254122).

Prehospital risk stratification in patients with chest pain.

OBJECTIVES: The History, ECG, Age, Risk Factors and Troponin (HEART) Score is a decision support tool applied by physicians in the emergency department developed to risk stratify low-risk patients presenting with chest pain. We assessed the potential value of this tool in prehospital setting, when applied by emergency medical services (EMS), and derived and validated a tool adapted to the prehospital setting in order to determine if it could assist with decisions regarding conveyance to a hospital. METHODS: In 2017, EMS personnel prospectively determined the HEART Score, including point-of-care (POC) troponin measurements, in patients presenting with chest pain, in the north of the Netherlands. The primary endpoint was a major adverse cardiac event (MACE), consisting of acute myocardial infarction or death, within 3 days. The components of the HEART Score were evaluated for their discriminatory value, cut-offs were calibrated for the prehospital setting and sex was substituted for cardiac risk factors to develop a prehospital HEART (preHEART) Score. This score was validated in an independent prospective cohort of 435 patients in 2018. RESULTS: Among 1208 patients prospectively recruited in the first cohort, 123 patients (10.2%) developed a MACE. The HEART Score had a negative predictive value (NPV) of 98.4% (96.4-99.3), a positive predictive value (PPV) of 35.5% (31.8-39.3) and an area under the receiver operating characteristic curve (AUC) of 0.81 (0.78-0.85). The preHEART Score had an NPV of 99.3% (98.1-99.8), a PPV of 49.4% (42.0-56.9) and an AUC of 0.85 (0.82-0.88), outperforming the HEART Score or POC troponin measurements on their own. Similar results were found in a validation cohort. CONCLUSIONS: The HEART Score can be used in the prehospital setting to assist with conveyance decisions and choice of hospitals; however, the preHEART Score outperforms both the HEART Score and single POC troponin measurements when applied by EMS personnel in the prehospital setting.

Case report regarding the evolution of electrocardiographic and echocardiographic features in cardiac amyloidosis.

BACKGROUND: Cardiac amyloidosis is an important cause for heart failure with preserved ejection fraction. It is often under diagnosed due to the fact that clinicians do not always recognize the specific diagnostic findings associated with this disease, also leading to the wrong diagnosis. When left untreated further irreversible organ dysfunction occurs, with high morbidity and mortality rates. CASE SUMMARY: A 71-year-old patient presented with progressive exertional dyspnoea and angina pectoris at the outpatient clinic. Medical history noted a percutaneous coronary intervention of the right coronary artery due to stable angina pectoris. The electrocardiogram showed low voltage in the limb leads and pseudo-infarct pattern in the precordial leads. Echocardiographic findings included left and right ventricular hypertrophy, decreased left ventricular systolic function, restrictive diastolic function, and 'relative' apical sparing of the left ventricle. This led to the suspicion of cardiac amyloidosis, which was confirmed with a positive bone scintigraphy using 99mTechnecium-DPD and the absence of monoclonal proteins. Treatment with Tafamidis was initiated. DISCUSSION: Electrocardiographic findings suggestive of cardiac amyloidosis are low voltage in the limb leads and/or a pseudo-infarct pattern in the precordial leads. Important echocardiographic findings are left and right ventricular hypertrophy, restrictive diastolic function, 'relative' apical sparing of the left ventricle and impaired left atrial strain. The next step in confirming the diagnosis is 99mTechnecium PYP/DPD/HMDP bone scintigraphy and testing for monoclonal proteins. The diagnosis ATTR amyloidosis is confirmed by the combination of positive bone scintigraphy (Perugini Grade 2 or 3) and the absence of monoclonal proteins, without the necessity of performing an endomyocardial biopsy.

Thermodilution-Based Invasive Assessment of Absolute Coronary Blood Flow and Microvascular Resistance: Quantification of Microvascular (Dys)Function?

During the last two decades, there has been a sharp increase in both interest and knowledge about the coronary microcirculation. Since these small vessels are not visible by the human eye, physiologic measurements should be used to characterize their function. The invasive methods presently used (coronary flow reserve (CFR) and index of microvascular resistance (IMR)) are operator-dependent and mandate the use of adenosine to induce hyperemia. In recent years, a new thermodilution-based method for measurement of absolute coronary blood flow and microvascular resistance has been proposed and initial procedural problems have been overcome. Presently, the technique is easy to perform using the Rayflow infusion catheter and the Coroventis software. The method is accurate, reproducible, and completely operator-independent. This method has been validated noninvasively against the current golden standard for flow assessment: Positron Emission Tomography-Computed Tomography (PET-CT). In addition, absolute flow and resistance measurements have proved to be safe, both periprocedurally and at long-term follow-up. With an increasing number of studies being performed, this method has great potential for better understanding and quantification of microvascular disease.

Inducible cardiac ischaemia is related to a decrease in the whole-blood Toll-like receptor 2 and 4 response.

TLR (Toll-like receptor) activation-induced inflammatory responses are important in the progression of atherosclerosis. We previously showed that TLR-dependent leucocyte responsiveness is acutely attenuated following percutaneous coronary intervention or vascular surgery. Furthermore, cytokine release following whole-blood TLR-2 and TLR-4 stimulation is negatively correlated with fractional flow reserve, suggesting that chronic ischaemia can elicit an enhanced inflammatory response. In the present study, we assessed the association between leucocyte TLR-2 and TLR-4 responsiveness and pre-existent and inducible ischaemia in patients undergoing SPECT (single-photon emission computed tomography)-MPI (myocardial perfusion imaging). TLR-2, TLR-4 and CD11b expression on monocytes were measured in blood samples that were obtained from 100 patients with suspected coronary artery disease before and after myocardial stress testing for SPECT-MPI. IL-8 (interleukin-8) levels were determined after whole-blood stimulation with Pam3Cys (TLR-2) and LPS (lipopolysaccharide; TLR-4). On the basis of SPECT-MPI, patients were categorized into three groups: reversible defect, irreversible defect and no defect. Myocardial stress induced a reduction in TLR-4 expression (2.46±0.21 compared with 2.17±0.16 arbitrary units, P=0.001) and CD11b expression (83.2±1.73 compared with 76.0±1.89 arbitrary units, P<0.001). TLR-induced IL-8 production before myocardial stress induction was not associated with the results of SPECT-MPI. However, a significant decrease in IL-8 production following TLR stimulation was observed after stress, which was more pronounced in patients with a reversible defect. In conclusion, inducible ischaemia is associated with a decrease in whole-blood TLR-2 and TLR-4 response. These results point to a regulating role of TLRs in order to prevent excessive inflammatory events known to occur during acute ischaemia.