Prevalence of coronary macro- and micro-vascular dysfunctions after drug-eluting stent implantation without in-stent restenosis

Evaluation of microcirculatory protection in percutaneous revascularisation: A stent implantation technique and device comparison

BACKGROUND

Coronary microvascular dysfunction (CMD) after percutaneous coronary intervention (PCI) is prognostically important and may also be a cause of persistent angina. The stent balloon inflation technique or material properties may influence the degree of CMD post-PCI.

METHODS

Thirty-six patients with stable angina attending for elective PCI were randomized to either slow drug eluting stent (DES) implantation technique (DES slow group): +2 atm. every 5 s., maintained for a further 30 s or a standard stent implantation technique (DES std group): rapid inflation and deflation. PressureWire X with thermodilution at rest and hyperemia and optical coherence tomography (OCT) were performed pre- and post-PCI. Combined primary endpoints were changes in index of microvascular resistance (delta IMR) and coronary flow reserve (delta CFR) following PCI. The secondary endpoints included differences in cardiac troponin I (delta cTnI) at 6 h post-PCI, Seattle angina questionnaire (SAQ) at 1, 3, 6, and 12 months and OCT measures of stent results immediately post-PCI and at 3 months.

RESULTS

Both groups were well matched, with similar baseline characteristics and OCT-defined plaque characteristics. Delta IMR was significantly better in the DES slow PCI arm with a median difference of -4.14 (95% CI -10.49, -0.39, p = 0.04). Delta CFR was also numerically higher with a median difference of 0.47 (95% CI -0.52, 1.31, p = 0.46). This did not translate to improved delta median cTnI (1.5 (34.8) vs. 0 (27.5) ng/L, p = 0.75) or median SAQ score at 3 months, (85 (20) vs. 95 (17.5), p = 0.47).

CONCLUSION

Slow stent implantation is associated with less CMD after elective PCI in patients with stable angina.

Benefits with drug-coated balloon as compared to a conventional revascularization strategy for the treatment of coronary and non-coronary arterial disease: a comprehensive meta-analysis of 45 randomized trials

BACKGROUND

Drug-coated balloons (DCB) have shown promising results for the percutaneous treatment of de novo and restenotic lesions, involving both the coronary and femoropopliteal district. However, clinical outcomes data associated with the use of this devices are still unclear, with potential warnings on increased mortality being raised from initial studies. We aimed at performing an updated and comprehensive meta-analysis comparing DCB with conventional percutaneous revascularization strategies for the treatment of coronary (CAD) or peripheral artery disease (PAD).

METHODS

Literature and main scientific session abstracts were searched for studies comparing DCB vs a standard percutaneous revascularization strategy, with or without stenting, for the treatment of CAD and PAD. The primary efficacy endpoint was mortality. Secondary endpoints were recurrent acute ischemic events (myocardial infarction or amputation) or target lesion revascularization (TLR).

RESULTS

We included 45 randomized trials, (CAD: 27 studies, PAD: 18 studies) with an overall population of 7718 patients, (56.4%) randomized to a DCB strategy. At a mean follow-up of19.3 ± 15.2 months, death occurred in 5.8% of the patients, with no significant difference between DCB or conventionally treated patients (5.9% vs 5.7%, OR[95%CI] = 0.89[0.71,1.11], p = 0.31; phet = 0.43). We observed a non-significant reduction in recurrent acute ischemic events, whereas the use of DCB significantly reduced the rate of TLR, with larger benefits observed in patients with PAD and respect to balloon-only angioplasty, while being lower in comparison with stent implantation. No significant interaction was observed with de novo lesions or in-stent restenosis.

CONCLUSIONS

Based on the current meta-analysis, the use of drug-coated balloons for the percutaneous treatment of CAD and PAD is associated to a comparable risk of mortality and recurrent acute ischemic events as compared to a conventional revascularization strategy, although offering larger benefits in terms of TLR, especially when compared with balloon-only angioplasty and in femoropopliteal disease.

Prognostic Impacts of Comorbid Significant Coronary Stenosis and Coronary Artery Spasm in Patients With Stable Coronary Artery Disease

BACKGROUND Stable coronary artery disease is caused by a variable combination of organic coronary stenosis and functional coronary abnormalities, such as coronary artery spasm. Thus, we examined the clinical importance of comorbid significant coronary stenosis and coronary spasm. METHODS AND RESULTS We enrolled 236 consecutive patients with suspected angina who underwent acetylcholine provocation testing for coronary spasm and fractional flow reserve (FFR) measurement. Among them, 175 patients were diagnosed as having vasospastic angina (VSA), whereas the remaining 61 had no VSA (non-VSA group). The patients with VSA were further divided into the following 3 groups based on angiography and FFR: no organic stenosis (≤50% luminal stenosis; VSA-alone group, n=110), insignificant stenosis of FFR>0.80 (high-FFR group, n=36), and significant stenosis of FFR≤0.80 (low-FFR group, n=29). The incidence of major adverse cardiovascular events, including cardiovascular death, nonfatal myocardial infarction, urgent percutaneous coronary intervention, and hospitalization attributed to unstable angina was evaluated. All patients with VSA received calcium channel blockers, and 28 patients (95%) in the low-FFR group underwent a planned percutaneous coronary intervention. During a median follow-up period of 656 days, although the incidence of major adverse cardiovascular events was low and comparable among non-VSA, VSA-alone, and high-FFR groups, the low-FFR group had an extremely poor prognosis (non-VSA group, 1.6%; VSA-alone group, 3.6%; high-FFR group, 5.6%; low-FFR group, 27.6%) (P<0.001). Importantly, all 8 patients with major adverse cardiovascular events in the low-FFR group were appropriately treated with percutaneous coronary intervention and calcium channel blockers. CONCLUSIONS These results indicate that patients with VSA with significant coronary stenosis represent a high-risk population despite current guideline-recommended therapies, suggesting the importance of routine coronary functional testing in this population.

Coronary microvascular dysfunction in stable ischaemic heart disease (non-obstructive coronary artery disease and obstructive coronary artery disease)

Diffuse and focal epicardial coronary disease and coronary microvascular abnormalities may exist side-by-side. Identifying the contributions of each of these three players in the coronary circulation is a difficult task. Yet identifying coronary microvascular dysfunction (CMD) as an additional player in patients with coronary artery disease (CAD) may provide explanations of why symptoms may persist frequently following and why global coronary flow reserve may be more prognostically important than fractional flow reserve measured in a single vessel before percutaneous coronary intervention. This review focuses on the challenges of identifying the presence of CMD in the context of diffuse non-obstructive CAD and obstructive CAD. Furthermore, it is going to discuss the pathophysiology in this complex situation, examine the clinical context in which the interaction of the three components of disease takes place and finally look at non-invasive diagnostic methods relevant for addressing this question.

Stent thrombosis in acute coronary syndromes: Patient-related factors and operator-related factors

OBJECTIVE

Stent thrombosis (ST) is a common phenomenon in acute coronary syndromes (ACS) when compared to stable coronary artery disease. This study analyzed the patient- and operator-related risk factors of ST in ACS.

METHODS

Coronary angiograms of 1738 consecutive ACS patients admitted in a large tertiary center between year 2014 and 2016 were analyzed retrospectively for the presence of ST. The paired angiograms [ST in ACS during and after percutaneous coronary intervention (PCI)] of the patients were analyzed by two independent observers, with focus on lesion characteristics and procedure techniques. Clinical and laboratory data were collected.

RESULTS

Stent thrombosis was found in 29 (1.6%) ACS patients, with a combination of at least one clinical/laboratory risk factor and one lesion/operator risk factor identified in 28 (96%) out of the 29 ACS patients with ST. The following risk factors for ST were found: Renal insufficiency (OR=4.14, p<0.001, 95% CI=1.73-9.88), type 2 diabetes (OR=2.21, p=0.034, 95% CI=1.06-4.61), excessive alcohol consumption (OR=3.12, p=0.023, 95% CI=1.17-8.33), stent implantation for ST-elevation myocardial infarction (STEMI) (OR=2.28, p=0.029, 95% CI=1.08-4.81), left main (LM) or left anterior descending artery (LAD) as culprit lesion (OR=2.80, p=0.010, CI 95%=1.27-5.95), and absence of antiplatelet therapy prior to ST (OR=3.58, p=0.002, 95% CI=1.60-7.96). The following lesion/operator possible risk factors were identified: Bifurcation lesion (n=7; 24%), heavy coronary calcifications (n=13; 44%), in-stent restenosis with secondary plate rupture (n=6, 20%), inappropriate stent size selection (n=6, 20%), and errors in periprocedural drug administration (n=4, 14%).

CONCLUSION

ST occurred in 1/62 ACS patients after PCI. A combination of clinical/laboratory and lesion/operator risk factors were present in almost all ACS patients with ST. This finding may support the search for strictly individualized strategies for the treatment of ACS patients with ST after PCI.

Mechanisms and diagnostic evaluation of persistent or recurrent angina following percutaneous coronary revascularization

Persistence or recurrence of angina after a percutaneous coronary intervention (PCI) may affect about 20-40% of patients during short-medium-term follow-up. This appears to be true even when PCI is 'optimized' using physiology-guided approaches and drug-eluting stents. Importantly, persistent or recurrent angina post-PCI is associated with a significant economic burden. Healthcare costs may be almost two-fold higher among patients with persistent or recurrent angina post-PCI vs. those who become symptom-free. However, practice guideline recommendations regarding the management of patients with angina post-PCI are unclear. Gaps in evidence into the mechanisms of post-PCI angina are relevant, and more research seems warranted. The purpose of this document is to review potential mechanisms for the persistence or recurrence of angina post-PCI, propose a practical diagnostic algorithm, and summarize current knowledge gaps.

Prevalence of Decreased Myocardial Blood Flow in Symptomatic Patients with Patent Coronary Stents: Insights from Low-Dose Dynamic CT Myocardial Perfusion Imaging

OBJECTIVE

To study the prevalence and clinical characteristics of decreased myocardial blood flow (MBF) quantified by dynamic computed tomography (CT) myocardial perfusion imaging (MPI) in symptomatic patients without in-stent restenosis.

MATERIALS AND METHODS

Thirty-seven (mean age, 71.3 ± 10 years; age range, 48-88 years; 31 males, 6 females) consecutive symptomatic patients with patent coronary stents and without obstructive de novo lesions were prospectively enrolled to undergo dynamic CT-MPI using a third-generation dual-source CT scanner. The shuttle-mode acquisition technique was used to image the complete left ventricle. A bolus of contrast media (50 mL; iopromide, 370 mg iodine/mL) was injected into the antecubital vein at a rate of 6 mL/s, followed by a 40-mL saline flush. The mean MBF value and other quantitative parameters were measured for each segment of both stented-vessel territories and reference territories. The MBF_ratio was defined as the ratio of the mean MBF value of the whole stent-vessel territory to that of the whole reference territory. An MBF_ratio of 0.85 was used as the cut-off value to distinguish hypoperfused from non-hypoperfused segments.

RESULTS

A total of 629 segments of 37 patients were ultimately included for analysis. The mean effective dose of dynamic CT-MPI was 3.1 ± 1.2 mSv (range, 1.7-6.3 mSv). The mean MBF of stent-vessel territories was decreased in 19 lesions and 81 segments. Compared to stent-vessel territories without hypoperfusion, the mean MBF and myocardial blood volume were markedly lower in hypoperfused stent-vessel territories (77.5 ± 16.6 mL/100 mL/min vs. 140.4 ± 24.1 mL/100 mL/min [p < 0.001] and 6.4 ± 3.7 mL/100 mL vs. 11.5 ± 4 mL/100 mL [p < 0.001, respectively]). Myocardial hypoperfusion in stent-vessel territories was present in 48.6% (18/37) of patients. None of clinical parameters differed statistically significantly between hypoperfusion and non-hypoperfusion subgroups.

CONCLUSION

Decreased MBF is commonly present in patients who are symptomatic after percutaneous coronary intervention, despite patent stents and can be detected by dynamic CT-MPI using a low radiation dose.

The number of stents was an independent risk of stent restenosis in patients undergoing percutaneous coronary intervention

Percutaneous coronary intervention (PCI) is one of the most effective therapies for coronary artery disease, but stent restenosis remains an important clinical challenge. The studies about the independent effect of the number of stents on stent restenosis were limited.The purpose was to identify the independent effect of the number of stents on stent restenosis.A retrospective cohort study of data reuse.From July 2009 to August 2011, a total of 2338 cases met the inclusion and exclusion criteria.The univariate analysis showed that the number of stents was a risk of stent restenosis, the OR value was 1.30 (95% CI:1.15 to 1.47, P < .001). The multi-factor regression analysis also showed that the number of stents was an independent risk of stent restenosis, the adjusted OR value was 1.38 (95% CI: 1.15 to 1.66, P < .001).Compared with 1-2 stents, the adjusted OR values of 3-5 stents and more than 6 stents were respectively 2.20 (95% CI: 1.24 to 3.90, P = .007) and 5.33 (95% CI: 1.89 to 15.08, P = .002), and the trend adjusted OR values was 2.26 (95% CI: 1.43 to 3.59, P < .001).The subgroup analysis of multi-factor regression analysis showed that when patients with the following conditions: 50 < Age, female, non-DES or SES, the risk of stent restenosis increased obviously.The number of stents was an independent risk of stent restenosis in patients undergoing PCI, especially for patients with the following conditions: 2<the number of stents, 50 < age, female, Non-DES (Drug-eluting stents) or SES (sirolimus-eluting stent).

Prognostic value of angiopoietin-2 for patients with coronary heart disease after elective PCI

Patients with coronary heart disease (CHD) frequently have cardiovascular complications after undergoing PCI. Angiopoietin-2 (Ang-2) is an important proangiogenic factor that also plays an important role in atherosclerosis. This study aimed to evaluate the value of Ang-2 in predicting cardiovascular events after elective PCI.This prospective study enrolled 97 patients with CHD who underwent elective PCI from 2013 to 2014. Blood samples were collected in the first morning after admission and within 24 to 48 h after PCI. The primary endpoint was cardiovascular events, defined as a composite of cardiac death, nonfatal myocardial infarction/repeat revascularization, readmission for severe deterioration of angina and readmission for new onset heart failure. Based on the median level of pre-PCI or post-PCI Ang-2, the patients were divided into a low level group and a high level group.During the whole follow-up period (mean, 53 ± 13 months), Kaplan-Meier curves of cardiovascular events showed that there was no significant difference between the two pre-PCI groups (χ = 2.22, P = .137, and log-rank test) or the two post-PCI groups (χ = 2.83, P = .093, and log-rank test). However, in a multivariable Cox regression model, landmark analysis showed that the patients in high level group of post-PCI, not pre-PCI, were associated with remarkable higher risks of cardiovascular events compared to the low level group during the first 1.5 years of follow-up (adjusted HR = 9.99, 95%CI = 1.99-50.13, P = .005). However, that was of no significance from 1.5 years to maximum follow-up years (adjusted HR = 0.82, 95%CI = 0.26-2.59, P = .733).High Ang-2 levels of post-PCI can predict the occurrence of cardiovascular events in the short to medium term.

Angina after percutaneous coronary intervention: The need for precision medicine

Persistence or recurrence of angina after successful percutaneous coronary intervention (PCI) represent an important clinical issue involving from one fifth to one third of patients undergoing myocardial revascularization at one-year follow-up. A systematic approach to this syndrome is strongly needed. Precision medicine is particularly important in addressing angina after successful PCI because of the multiple underlying causes. Restenosis or coronary atherosclerosis progression explain symptom recurrence after successful PCI in some patients, while functional causes, including vasomotor abnormalities of epicardial coronary arteries and/or coronary microvascular dysfunction, explain symptoms in the remaining patients. In this review, we summarize the mechanisms of persistent or recurrent angina after PCI, proposing a diagnostic algorithm and a systematic therapeutic approach.

CYP2C19 variants and epoxyeicosatrienoic acids in patients with microvascular angina

BACKGROUND

Categorization as a cytochrome P450 (CYP) 2C19 poor metabolizer (PM) is reported to be an independent risk factor for cardiovascular disease. Epoxyeicosatrienoic acids (EETs) are metabolites of arachidonic acid by CYP2C19 epoxygenases and anti-inflammatory properties, especially in microvascular tissues. We examined the impact of CYP2C19 polymorphisms and EETs on the patients with microvascular angina (MVA) caused by coronary microvascular dysfunction.

METHODS AND RESULTS

We examined CYP2C19 genotypes in patients with MVA (n = 81). MVA was defined as absence of coronary artery stenosis and epicardial spasms, and the presence of inversion of lactic acid levels between intracoronary and coronary sinuses in acetylcholine-provocation test or the adenosine-triphosphate-induced coronary flow reserve ratio was below 2.5. CYP2C19 PM have two loss-of-functon alleles (*2, *3). We measured serum dihydroxyeicosatrienoic acid (DHET) as representative EET metabolite. In MVA, the patients with CYP2C19 PM were 34.6% and high sense C-reactive protein (hs-CRP) levels in CYP2C19 PM were significantly higher than that of non-PM group (0.165 ± 0.116 vs. 0.097 ± 0.113 mg/dL, P = 0.026). Moreover, DHET levels in CYP2C19 PM were significantly lower than that of non-PM (10.4 ± 4.58 vs. 15.6 ± 11.1 ng/mL, P = 0.003 (11,12-DHET); 12.1 ± 3.79 vs. 17.3 ± 6.49 ng/mL, P = 0.019 (14,15-DHET)).

CONCLUSIONS

The decline of EET owing to CYP2C19 variants may affects coronary microvascular dysfunction via chronic inflammation.