Ten-Year Outcome of Recanalization or Medical Therapy for Concomitant Chronic Total Occlusion After Myocardial Infarction

BACKGROUND

The EXPLORE (Evaluating Xience and Left Ventricular Function in PCI on Occlusions After STEMI) trial was the first and only randomized trial investigating chronic total occlusion (CTO) percutaneous coronary intervention (PCI) early after primary PCI for ST-segment-elevation myocardial infarction, compared with medical therapy for the CTO. We performed a 10-year follow-up of EXPLORE to investigate long-term safety and clinical impact of CTO PCI after ST-segment-elevation myocardial infarction, compared with no-CTO PCI.

METHODS AND RESULTS

In EXPLORE, 302 patients post-ST-segment-elevation myocardial infarction with concurrent CTO were randomized to CTO PCI within ≈1 week or no-CTO PCI. We performed an extended clinical follow-up for the primary end point of major adverse cardiac events, consisting of cardiovascular death, coronary artery bypass grafting, or myocardial infarction. Secondary end points included all-cause death, angina, and dyspnea. Median follow-up was 10 years (interquartile range, 8-11 years). The primary end point occurred in 25% of patients with CTO PCI and in 24% of patients with no-CTO PCI (hazard ratio [HR], 1.11 [95% CI, 0.70-1.76]). Cardiovascular mortality was higher in the CTO PCI group (HR, 2.09 [95% CI, 1.10-2.50]), but all-cause death was similar (HR, 1.53 [95% CI, 0.93-2.50]). Dyspnea relief was more frequent after CTO PCI (83% versus 65%, P=0.005), with no significant difference in angina.

CONCLUSIONS

This 10-year follow-up of patients post-ST-segment-elevation myocardial infarction randomized to CTO PCI or no-CTO PCI demonstrated no clinical benefit of CTO PCI in major adverse cardiac events or overall mortality. However, CTO PCI was associated with a higher cardiovascular mortality compared with no-CTO PCI. Our long-term data support a careful weighing of effective symptom relief against an elevated cardiovascular mortality risk in CTO PCI decisions.

REGISTRATION

URL: https://www.trialregister.nl; Unique identifier: NTR1108.

Quantitative flow ratio versus fractional flow reserve for coronary revascularisation guidance (FAVOR III Europe): a multicentre, randomised, non-inferiority trial

BACKGROUND

Fractional flow reserve (FFR) or non-hyperaemic pressure ratios are recommended to assess functional relevance of intermediate coronary stenosis. Both diagnostic methods require the placement of a pressure wire in the coronary artery during invasive coronary angiography. Quantitative flow ratio (QFR) is an angiography-based computational method for the estimation of FFR that does not require the use of pressure wires. We aimed to investigate whether a QFR-based diagnostic strategy yields a non-inferior 12-month clinical outcome compared with an FFR-based strategy.

METHODS

FAVOR III Europe was a multicentre, randomised, open-label, non-inferiority trial comparing a QFR-based with an FFR-based diagnostic strategy for patients with intermediate coronary stenosis. Enrolment was performed in 34 centres across 11 European countries. Patients aged 18 years or older with either chronic coronary syndrome or stabilised acute coronary syndrome, and with at least one intermediate non-culprit stenosis (40-90% diameter stenosis by visual estimate; referred to here as a study lesion), were randomly assigned (1:1) to the QFR-guided or the FFR-guided group. Randomisation was done using a concealed web-based system and was stratified by diabetes and presence of a left anterior descending coronary artery study lesion. The primary endpoint was a composite of death, myocardial infarction, and unplanned revascularisation at 12 months. The predefined non-inferiority margin was 3·4% and the primary analysis was performed in the intention-to-treat population. The trial was registered with ClinicalTrials.gov (NCT03729739) and long-term follow-up is ongoing.

FINDINGS

Between Nov 6, 2018, and July 21, 2023, 2000 patients were enrolled and randomly assigned to the QFR-guided strategy (1008 patients) or the FFR-guided strategy (992 patients). The median age was 67·3 years (IQR 59·9-74·7); 1538 (76·9%) patients were male and 462 (23·1%) were female. Median follow-up time was 365 days (IQR 365-365). At 12 months, a primary endpoint event had occurred in 67 (6·7%) patients in the QFR group, and in 41 (4·2%) patients in the FFR group (hazard ratio 1·63 [95% CI 1·11-2·41]). The event proportion difference was 2·5% (90% two-sided CI 0·9-4·2). The upper limit of the 90% CI exceeded the prespecified non-inferiority margin of 3·4%. Therefore, QFR did not meet non-inferiority to FFR. A total of 18 (1·8%) patients in each group experienced an adverse procedural event, the most frequent being procedure-related myocardial infarction, which occurred in ten (1·0%) patients in the QFR group and seven (0·7%) in the FFR group. One patient in the QFR group died in relation to the index procedure.

INTERPRETATION

The results of the FAVOR III Europe trial do not support the use of QFR if FFR is available to guide revascularisation decisions in patients with intermediate coronary stenosis. This finding could have implications for current clinical guidelines recommending QFR for this purpose.

FUNDING

Medis Medical Imaging Systems and Aarhus University.

Beyond early LDL cholesterol lowering to prevent coronary atherosclerosis in familial hypercholesterolaemia

AIMS

Familial hypercholesterolaemia (FH) patients are subjected to a high lifetime exposure to low density lipoprotein cholesterol (LDL-C), despite use of lipid-lowering therapy (LLT). This study aimed to quantify the extent of subclinical atherosclerosis and to evaluate the association between lifetime cumulative LDL-C exposure and coronary atherosclerosis in young FH patients.

METHODS AND RESULTS

Familial hypercholesterolaemia patients, divided into a subgroup of early treated (LLT initiated <25 years) and late treated (LLT initiated ≥25 years) patients, and an age- and sex-matched unaffected control group, underwent coronary CT angiography (CCTA) with artificial intelligence-guided analysis. Ninety genetically diagnosed FH patients and 45 unaffected volunteers (mean age 41 ± 3 years, 51 (38%) female) were included. Familial hypercholesterolaemia patients had higher cumulative LDL-C exposure (181 ± 54 vs. 105 ± 33 mmol/L ∗ years) and higher prevalence of coronary plaque compared with controls (46 [51%] vs. 10 [22%], OR 3.66 [95%CI 1.62-8.27]). Every 75 mmol/L ∗ years cumulative exposure to LDL-C was associated with a doubling in per cent atheroma volume (total plaque volume divided by total vessel volume). Early treated patients had a modestly lower cumulative LDL-C exposure compared with late treated FH patients (167 ± 41 vs. 194 ± 61 mmol/L ∗ years; P = 0.045), without significant difference in coronary atherosclerosis. Familial hypercholesterolaemia patients with above-median cumulative LDL-C exposure had significantly higher plaque prevalence (OR 3.62 [95%CI 1.62-8.27]; P = 0.001), compared with patients with below-median exposure.

CONCLUSION

Lifetime exposure to LDL-C determines coronary plaque burden in FH, underlining the need of early as well as potent treatment initiation. Periodic CCTA may offer a unique opportunity to monitor coronary atherosclerosis and personalize treatment in FH.

Fibroblast growth factor 5: a novel biomarker for familial hypercholesterolaemia

BACKGROUND AND AIMS

Identification of individuals affected by familial hypercholesterolaemia (FH) is suboptimal when genetic tests are unavailable. Relying only on low-density lipoprotein cholesterol (LDL-C) is challenging as it may not allow distinguishing individuals with FH from hypercholesterolaemic (HC) individuals from the general population. The aim of this study was to determine whether biomarkers associated with cardiovascular disease and/or inflammation identify FH individuals and distinguish them from HC individuals.

METHODS

A panel of 264 proteins in plasma was measured and machine learning was used to search for those that can distinguish FH individuals, either genetically proven (genFH) or clinically diagnosed (clinFH) from HC and control individuals.

RESULTS

Both genFH and clinFH had elevated plasma levels of fibroblast growth factor 5 (FGF-5) compared with controls (mean area under the curve [AUC] > .990 for both, P < .001) or HC individuals (mean AUC >.990, P < .001), even after matching for LDL-C levels. An immunoenzymatic assay confirmed that FGF-5 was elevated in genFH and clinFH in all cohorts analysed.

CONCLUSIONS

This analysis suggests that FGF-5 could be a biomarker to discriminate individuals living with FH from HC individuals.

Residual quantitative flow ratio to estimate post-intervention fractional flow reserve

Objective

To assess the performance of residual quantitative flow ratio (QFR) to estimate post percutaneous coronary intervention (PCI) fractional flow reserve (FFR).

Background

QFR computes FFR based on invasive coronary angiography (ICA) images. Residual QFR is a novel tool that assesses the functional outcome of an intervention by estimating post-PCI FFR.

Methods

Residual QFR analyses, using pre-PCI ICA images, were attempted in 159 vessels with post-PCI FFR measurements. QFR lesion location was matched with the treated segment to allow virtual removal of the lesion similar to the performed PCI and computation of residual QFR (Picture 1: case example of residual QFR analysis). A post-PCI FFR &lt;0.90 was used to define a suboptimal PCI result.

Results

Residual QFR computation was successful in 128 (81%) vessels. Median residual QFR was higher than post-PCI FFR (0.96 interquartile range (IQR): 0.91–0.99 vs. 0.91 IQR: 0.86–0.96, p&lt;0.001). A moderate correlation and agreement was observed between residual QFR and post-PCI FFR (Spearman correlation coefficient=0.56 and Intraclass correlation coefficient=0.47, p&lt;0.001 for both). Following PCI, an FFR &lt;0.90 was observed in 54 (42%) vessels. Specificity, positive predictive value, sensitivity, and negative predictive value of residual QFR for determining a suboptimal PCI result were 96% (95% confidence interval (CI): 87–99%), 89% (95% CI: 72–96%), 44% (95% CI: 31–59%), and 70% (95% CI: 65–75%), respectively. Overall, residual QFR had an accuracy of 74% (95% CI: 66–82%) and an area under the receiver operating characteristic curve of 0.79 for assessing a post PCI FFR &lt;0.90.

Conclusion

A moderate correlation and agreement between residual QFR and post-PCI FFR was observed. Residual QFR ≥0.90 does not necessarily commensurate with an optimal PCI result. However, residual QFR &lt;0.90 is a good indicator of a post-PCI FFR &lt;0.90 and might therefore be utilized to determine PCI location in order to obtain a satisfactory PCI result (Picture 2: central illustration).

Funding Acknowledgement

Type of funding sources: None. Case example of residual QFR analysisCentral illustration

Defining the prognostic value of [15O]H2O positron emission tomography derived myocardial ischemic burden

Background

A myocardial ischemic burden (IB) of 10% is used to denote high-risk patients with coronary artery disease (CAD). This threshold has primarily been assessed by single-photon emission computed tomography. Differences in the pharmacokinetics of the utilized traces, higher resolution of positron emission tomography (PET), and lastly differences in assessment of IB might lead to a higher prognostic threshold for quantitative PET.

Purpose

To determine a [15O]H2O PET derived IB to identify low (annualized event rate (AER) &lt;1.0%) and high (AER ≥3%) risk CAD patients.

Methods

623 patients who underwent [15O]H2O PET because of suspected CAD and in whom follow-up was obtained were included. The IB was defined as the percentage of myocardium with a hyperemic blood flow (hMBF) ≤2.3 ml/min/g and by a coronary flow reserve (CFR) of ≤2.5. The endpoint was a composite of death and non-fatal myocardial infarction (MI). Time-dependent ROC curves were constructed for the prediction of the endpoint within the first 5-years, based on these curves thresholds were selected for which specificity was maximized and sensitivity was at least 80%. Patients were classified as having a high IB if their respective IBs were above the prognostic thresholds and as having a low IB if not.

Results

During a median follow-up of 6.7 years, 34 (6%) patients died and 28 (4%) experienced a MI resulting in 62 (10%) endpoints. An IB of 24% and 28% for hMBF and CFR, respectively, was found to be the optimal threshold to define prognosis. Patients with a high hMBF or high CFR IB had worse outcome compared to patients with a low IB (log-rank p&lt;0.001 for both), with AERs of 0.6% vs. 2.8%, and 0.6% vs. 2.4% (p&lt;0.001 for both), respectively. Patients with a concordantly high hMBF and CFR derived IB had the worst outcome (AER: 3.1%), whereas patients with a concordantly low or discordant IB result had a similarly low event rate of 0.5% and 0.9% (p=0.953), respectively (log-rank p=0.445). A concordantly high hMBF and CFR IB was an independent predictor of adverse outcome beyond clinical characteristics (adjusted hazard ratio: 3.52, p&lt;0.001).

Conclusion

An IB of 24% and 28% for hMBF and CFR was found to be the optimal prognostic threshold. Both measurements can be used to determine patients outcome. However combining hMBF and CFR IB results leads to a further refinement of risk-stratification allowing for the identification of low (concordant low or discordant IB result) and high (concordant high IB result) risk CAD patients.

Funding Acknowledgement

Type of funding source: None

Feasibility of planar myocardial carbon 11-acetate imaging

BACKGROUND

Myocardial oxygen consumption can be determined by using carbon 11-acetate (11C-acetate) and positron emission tomography (PET). The aim of this study was to validate planar 11C-acetate scintigraphy in healthy individuals by relating the myocardial clearance rate of dynamic 11C-acetate scintigraphy with the rate-pressure product, which is used as a measure of cardiac work. Also, the optimal curve-fitting procedure of the time-activity curve and the intraobserver and interobserver variation of determining the clearance rates were assessed.

METHODS AND RESULTS

Six subjects were studied at rest, and seven subjects were studied during dobutamine stimulation. Imaging was performed with a planar camera equipped with high-energy collimators for 45 minutes after the injection of 185 MBq of 11C-acetate. Myocardial time-activity curves were corrected for decay. During the study, heart rates and blood pressures were measured to calculate the rate-pressure product. Myocardial time-activity curves showed a clear biphasic pattern. Clearance rates were expressed in k values. The best fitting procedure, as assessed by means of the lowest error of k and the best correlation with the rate-pressure product, proved to be a monoexponential fit on the first part of the time-activity curve (kmono). Subjects studied during dobutamine infusion had significantly higher rate-pressure product (15.0 +/- 2.1*10(3) vs 8.6 +/- 1.2*10(3), P < .001) and 11C-acetate clearance rates (kmono = 0.0657 +/- 0.0110 vs 0.0313 +/- 0.0056, P < .0001) than subjects studied at rest. There was low intraobserver and interobserver variation in determining kmono values. A significant correlation between the rate-pressure product and the monoexponential clearance rate was found (kmono = 5.11*10(-6)*RPP-0.012; r = 0.94, P < .001).

CONCLUSIONS

The estimation of myocardial oxygen consumption is feasible with planar 11C-acetate scintigraphy. Clearance rates and the relation with the rate-pressure product are similar to those reported in PET studies. This technique may be used for the assessment and follow-up of global myocardial metabolic abnormalities, eg, in patients with hypertensive heart disease, cardiomyopathy, myocarditis, and valvular disease.

Perfusable tissue index as a potential marker of fibrosis in patients with idiopathic dilated cardiomyopathy

A varying degree of interstitial and perivascular fibrosis is a common finding in idiopathic dilated cardiomyopathy (DCM). The perfusable tissue index (PTI), obtained with PET, is a noninvasive tool for assessing myocardial fibrosis on a regional level. Measurements of the PTI in DCM, however, have not been performed yet. This study was undertaken to test the hypothesis that the PTI is reduced in patients with DCM.

METHODS

Fifteen patients with an advanced stage of DCM (New York Heart Association class III or IV and left ventricular ejection fraction [LVEF] < 35%) and 11 healthy control subjects were studied. PET was performed using H(2)(15)O and C(15)O to obtain the perfusable tissue fraction (PTF) and the anatomic tissue fraction (ATF), respectively.

RESULTS

The PTI (=PTF/ATF) was reduced in DCM compared with control subjects (0.91 +/- 0.12 vs. 1.12 +/- 0.10; P < 0.01). Heterogeneity of the PTI, expressed as the coefficient of variation, was increased in DCM versus that of healthy control subjects (0.18 +/- 0.07 vs. 0.13 +/- 0.06; P < 0.05). There was no correlation between the PTI and echocardiographically derived LVEF in both groups.

CONCLUSION

The PTI was reduced in patients with an advanced stage of DCM. Interstitial and perivascular fibrosis may be responsible for this reduction. Furthermore, the degree of the PTI reduction was variable in DCM patients, both on a regional level and between patients. Noninvasive assessment of fibrosis with the PTI offers the opportunity to evaluate the effects of fibrosis on regional myocardial function, correlate fibrosis with prognosis, and monitor pharmaceutical intervention.

Outcomes of 7560 chronic total occlusion patients undergoing percutaneous coronary intervention: results from a Dutch nationwide registry

Background

The presence of a chronic total coronary occlusion (CTO) is associated with worse clinical outcomes. We aimed to identify CTO patients that are at risk of these outcomes in a nationwide registry.

Methods

The Netherlands Heart Registration (NHR) is a nationwide registry that registers outcomes of cardiac interventions. For the purpose of this analysis, the data of all patients undergoing PCI from inception of the NHR to December 2019 were selected, that included PCI with at least one CTO in one of the treated coronary arteries. We used multivariate logistic regression of baseline characteristics for the outcome measures target vessel revascularization (TVR) &lt;1 year, 30-day myocardial infarction (MI) and 1-year mortality. The impact of the assessed risk factors on outcomes was described as odds ratio (OR) with corresponding 95% confidence intervals (CI).

Results

A total of 7560 patients underwent PCI with ≥1 CTO in one of the treated arteries between January 1, 2015 until December 31, 2018 (mean age 65±10 years, 77.4% male [n=5850]). Five percent of patients deceased within 1 year after PCI (n=375), TVR&lt;1 year occurred in 11% (n=525/4804) and 30-day MI occurred in 0.5% (25/4985). In multivariate regression, the only predictor for TVR&lt;1 year was the presence of diabetes mellitus (OR 1.29, 95% CI 1.06–1.56). Predictors for the outcome MI &lt;30 days were female gender (OR 2.24, 95% CI 1.05–4.79), chronic kidney disease (OR 3.94, 95% CI 1.15–13.50) and cardiogenic shock at presentation (OR 7.94, 95% CI 2.28–27.7). Strong predictors for 1 year mortality were the presence of cardiogenic shock at presentation (OR 17.86, 95% CI 2.90–109.92) and the presence of chronic kidney disease (OR 4.56, 95% CI 2.04–10.16), other predictors were age (OR 1.04, 95% CI 1.01–1.07), female gender (OR 1.83, 95% CI 1.08–3.10), diabetes (OR 1.66, 95% CI 1.01–2.73) and left ventricular ejection fraction (LVEF; OR 0.95, 95% CI 0.93–0.97).

Conclusion

In this nationwide registry of 7560 CTO patients undergoing PCI, cardiogenic shock and chronic kidney disease were strong predictors for 1 year mortality and 30 day MI. Diabetes mellitus was the only predictor for the occurrence of TVR &lt;1 year. Identification of patients at risk for poor clinical outcomes may help improve the outcomes of CTO patients in the future.

Funding Acknowledgement

Type of funding source: None