Impact of arterial injury on neointimal hyperplasia after implantation of drug-eluting stents in coronary arteries: an intravascular ultrasound study

Aims: We investigated the impact of arterial injury on neointimal hyperplasia following implantation of drug-eluting stents (DES). Methods and results: A total of 196 patients with 223 segments (sirolimus-eluting stents [SES]: 104, paclitaxel-eluting stents [PES]: 119) underwent intravascular ultrasound eight months after DES implantation. Arterial injury was defined as the balloon-to-artery ratio (BAR). Segments were categorised into two groups: high BAR defined as BAR>1.1 (120 segments), and low BAR defined as BAR ≤1.1 (103 segments). Baseline clinical characteristics were similar for both groups. Although reference vessel diameter was smaller, stent diameter, maximal balloon pressure and balloon diameter were higher in the high BAR compared with the low BAR group. Lumen (7.10±1.91 vs. 6.25±1.69, p=0.001), stent (7.31±1.95 vs. 6.41±1.80, p=0.001), and external elastic membrane (17.1±4.9 vs. 14.8±4.0, p<0.0001) areas (mm2) were higher, but neointimal hyperplasia (0.21±0.36 vs. 0.16±0.48, p=0.42) area (mm2) was similar in the high BAR compared with the low BAR group. Arterial injury as assessed by BAR was not associated with the amount of neointimal hyperplasia (R2=0.003, p=0.40). Conclusions: Arterial injury does not correlate with the amount of neointimal hyperplasia following DES implantation. Conventionally aggressive DES implantation techniques do not adversely affect long-term outcome with respect to restenosis. - See more at: http://www.pcronline.com/eurointervention/30th_issue/79/#sthash.1do4X31G.dpuf

Safety of diagnostic balloon occlusion in normal coronary arteries

Diagnostic coronary balloon occlusion (CBO) is mandatory for collateral function assessment, during angioscopy and optical coherence imaging, and when using certain coronary protection devices against emboli. Thus far, the safety of diagnostic CBO regarding procedural and long-term complications in normal coronary arteries has not been studied. In 316 patients, diagnostic CBO was performed for collateral function measurement in 426 angiographically normal vessels. The angioplasty balloon was inflated for 60 to 120 seconds using inflation pressures of 1 to 3 atm, followed by control angiography during and after CBO. Patients were divided into groups with entirely normal (n = 133) and partially normal (n = 183) vessels. Primary end points were procedural and long-term complications. De novo stenosis development was assessed by quantitative coronary angiography in 35% of the patients. Secondary end points were cardiac events at 5 years of follow-up. Procedural complications occurred in 1 patient (0.2%). In 150 repeat angiographic procedures in 92 patients (follow-up duration 10 +/- 15 months), quantitative coronary angiography revealed no difference in percentage diameter narrowing between baseline and follow-up (4.1% vs 3.9%, p = 0.69). During follow-up periods of 14 and 72 months, respectively, a new stenotic lesion was detected in 1 patient in each group (1.3%). Major cardiac events and percutaneous coronary intervention for stable angina were less frequent in the group with entirely normal than with partially normal vessels (0.8% vs 5.5%, p = 0.02, and 0.8% vs 18%, p <0.0001). In conclusion, low-inflation pressure diagnostic CBO in angiographically normal coronary arteries bears a minimal risk for procedural and long-term complications and can therefore be regarded as a safe procedure.

Vascular tissue reaction to acute malapposition in human coronary arteries: sequential assessment with optical coherence tomography

The vascular tissue reaction to acute incomplete stent apposition (ISA) is not well known. The aim of this study was to characterize the vascular response to acute ISA in vivo and to look for predictors of incomplete healing.

Instant percutaneous closure of patent foramen ovale in patients with acute myocardial infarction and normal coronary arteries

Two young women with angiographically normal coronary arteries suffered an acute myocardial infarction. Both were found to have a patent foramen ovale (PFO), the likely pathway of a paradoxical embolus causing the infarction. The PFOs were diagnosed and closed percutaneously with an Amplatzer PFO Occluder during the emergency coronary angiography.

Temporary scaffolding of coronary arteries with bioabsorbable magnesium stents: a prospective, non-randomised multicentre trial

BACKGROUND: Coronary stents improve immediate and late results of balloon angioplasty by tacking up dissections and preventing wall recoil. These goals are achieved within weeks after angioplasty, but with current technology stents permanently remain in the artery, with many limitations including the need for long-term antiplatelet treatment to avoid thrombosis. We report a prospective multicentre clinical trial of coronary implantations of absorbable magnesium stents. METHODS: We enrolled 63 patients (44 men; mean age 61.3 [SD 9.5 years]) in eight centres with single de novo lesions in a native coronary artery in a multicentre, non-randomised prospective study. Follow-up included coronary angiography and intravascular ultrasound at 4 months and clinical assessment at 6 months and 12 months. The primary endpoint was cardiac death, non-fatal myocardial infarction, or clinically driven target lesion revascularisation at 4 months FINDINGS: 71 stents, 10-15 mm in length and 3.0-3.5 mm in diameter, were successfully implanted after pre-dilatation in 63 patients. Diameter stenosis was reduced from 61.5 (SD 13.1%) to 12.6 (5.6%) with an acute gain of 1.41 mm (0.46 mm) and in-stent late loss of 1.08 mm (0.49 mm). The ischaemia-driven target lesion revascularisation rate was 23.8% after 4 months, and the overall target lesion revascularisation rate was 45% after 1 year. No myocardial infarction, subacute or late thrombosis, or death occurred. Angiography at 4 months showed an increased diameter stenosis of 48.4 (17.0%). After serial intravascular ultrasound examinations, only small remnants of the original struts were visible, well embedded into the intima. Neointimal growth and negative remodelling were the main operating mechanisms of restenosis. INTERPRETATION: This study shows that biodegradable magnesium stents can achieve an immediate angiographic result similar to the result of other metal stents and can be safely degraded after 4 months. Modifications of stent characteristics with prolonged degradation and drug elution are currently in development.

Early- and long-term intravascular ultrasound and angiographic findings after bioabsorbable magnesium stent implantation in human coronary arteries

OBJECTIVES: This study aimed to evaluate the degradation rate and long-term vascular responses to the absorbable metal stent (AMS). BACKGROUND: The AMS demonstrated feasibility and safety at 4 months in human coronary arteries. METHODS: The PROGRESS-AMS (Clinical Performance and Angiographic Results of Coronary Stenting) was a prospective, multicenter clinical trial of 63 patients with coronary artery disease who underwent AMS implantation. Angiography and intravascular ultrasound (IVUS) were conducted immediately after AMS deployment and at 4 months. Eight patients who did not require repeat revascularization at 4 months underwent late angiographic and IVUS follow-up from 12 to 28 months. RESULTS: The AMS was well-expanded upon deployment without immediate recoil. The major contributors for restenosis as detected by IVUS at 4 months were: decrease of external elastic membrane volume (42%), extra-stent neointima (13%), and intra-stent neointima (45%). From 4 months to late follow-up, paired IVUS analysis demonstrated complete stent degradation with durability of the 4-month IVUS indexes. The neointima was reduced by 3.6 +/- 5.2 mm(3), with an increase in the stent cross sectional area of 0.5 +/- 1.0 mm(2) (p = NS). The median in-stent minimal lumen diameter was increased from 1.87 to 2.17 mm at long-term follow-up. The median angiographic late loss was reduced from 0.62 to 0.40 mm by quantitative coronary angiography from 4 months to late follow-up. CONCLUSIONS: Intravascular ultrasound imaging supports the safety profile of AMS with degradation at 4 months and maintains durability of the results without any early or late adverse findings. Slower degradation is warranted to provide sufficient radial force to improve long-term patency rates of the AMS.

Distinct roles of estrogen receptors alpha and beta mediating acute vasodilation of epicardial coronary arteries.

This study investigated the contribution of estrogen receptors (ERs) alpha and beta for epicardial coronary artery function, vascular NO bioactivity, and superoxide (O(2)(-)) formation. Porcine coronary rings were suspended in organ chambers and precontracted with prostaglandin F(2alpha) to determine direct effects of the selective ER agonists 4,4',4''-(4-propyl-[(1)H]pyrazole-1,3,5-triyl)tris-phenol (PPT) or 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) or the nonselective ER agonist 17beta-estradiol. Indirect effects on contractility to U46619 and relaxation to bradykinin were assessed and effects on NO, nitrite, and O(2)(-) formation were measured in cultured cells. Within 5 minutes, selective ERalpha activation by PPT, but not 17beta-estradiol or the ERbeta agonist DPN, caused rapid, NO-dependent, and endothelium-dependent relaxation (49+/-5%; P<0.001 versus ethanol). PPT also caused sustained endothelium- and NO-independent vasodilation similar to 17beta-estradiol after 60 minutes (72+/-3%; P<0.001 versus ethanol). DPN induced endothelium-dependent NO-independent relaxation via endothelium-dependent hyperpolarization (40+/-4%; P<0.01 versus ethanol). 17beta-Estradiol and PPT, but not DPN, attenuated the responses to U46619 and bradykinin. All of the ER agonists increased NO and nitrite formation in vascular endothelial but not smooth muscle cells and attenuated vascular smooth muscle cell O(2)(-) formation (P<0.001). ERalpha activation had the most potent effects on both nitrite formation and inhibiting O(2)(-) (P<0.05). These data demonstrate novel and differential mechanisms by which ERalpha and ERbeta activation control coronary artery vasoreactivity in males and females and regulate vascular NO and O(2)(-) formation. The findings indicate that coronary vascular effects of sex hormones differ with regard to affinity to ERalpha and ERbeta, which will contribute to beneficial and adverse effects of hormone replacement therapy.

Electrocardiographic ST-segment monitoring during controlled occlusion of coronary arteries

Background: Ischemia monitoring cannot always be performed by 12-lead ECG. Hence, the individual performance of the ECG leads is crucial. No experimental data on the ECG's specificity for transient ischemia exist. Methods: In 45 patients a 19-lead ECG was registered during a 1-minute balloon occlusion of a coronary artery (left anterior descending artery [LAD], right coronary artery [RCA] or left circumflex artery [LCX]). ST-segment shifts and sensitivity/specificity of the leads were measured. Results: During LAD occlusion, V3 showed maximal ST-segment elevation (0.26 mV [IQR 0.16–0.33 mV], p = 0.001) and sensitivity/specificity (88% and 80%). During RCA occlusion, III showed maximal ST-elevation (0.2 mV [IQR 0.09–0.26 mV], p = 0.004), aVF had the best sensitivity/specificity (85% and 68%). During LCX occlusion, V6 showed maximal ST-segment elevation (0.04 mV [IQR 0.02–0.14 mV], p = 0.005), and sensitivity/specificity was (31%/92%) but could be improved (63%/72%) using an optimized cut-off for ischemia. Conclusion: V3, aVF and V6 show the best performance to detect transient ischemia.

Effect of high-intensity statin therapy on atherosclerosis in non-infarct-related coronary arteries (IBIS-4): a serial intravascular ultrasonography study

AIM The effect of long-term high-intensity statin therapy on coronary atherosclerosis among patients with acute ST-segment elevation myocardial infarction (STEMI) is unknown. The aim of this study was to quantify the impact of high-intensity statin therapy on plaque burden, composition, and phenotype in non-infarct-related arteries of STEMI patients undergoing primary percutaneous coronary intervention (PCI). METHODS AND RESULTS Between September 2009 and January 2011, 103 STEMI patients underwent intravascular ultrasonography (IVUS) and radiofrequency ultrasonography (RF-IVUS) of the two non-infarct-related epicardial coronary arteries (non-IRA) after successful primary PCI. Patients were treated with high-intensity rosuvastatin (40 mg/day) throughout 13 months and serial intracoronary imaging with the analysis of matched segments was available for 82 patients with 146 non-IRA. The primary IVUS end-point was the change in per cent atheroma volume (PAV). After 13 months, low-density lipoprotein cholesterol (LDL-C) had decreased from a median of 3.29 to 1.89 mmol/L (P < 0.001), and high-density lipoprotein cholesterol (HDL-C) levels had increased from 1.10 to 1.20 mmol/L (P < 0.001). PAV of the non-IRA decreased by -0.9% (95% CI: -1.56 to -0.25, P = 0.007). Patients with regression in at least one non-IRA were more common (74%) than those without (26%). Per cent necrotic core remained unchanged (-0.05%, 95% CI: -1.05 to 0.96%, P = 0.93) as did the number of RF-IVUS defined thin cap fibroatheromas (124 vs. 116, P = 0.15). CONCLUSION High-intensity rosuvastatin therapy over 13 months is associated with regression of coronary atherosclerosis in non-infarct-related arteries without changes in RF-IVUS defined necrotic core or plaque phenotype among STEMI patients.

Chlamydia pneumoniae (TWAR) in coronary arteries of young adults (15-34 years old).

An association of Chlamydia pneumoniae with atherosclerosis of coronary and carotid arteries and aorta has been found by seroepidemiology and by demonstration of the organism in atheromata. Age-matched control tissue from persons without atherosclerosis was usually not available. We studied autopsy tissue from young persons, many with no atherosclerosis, to determine whether C. pneumoniae is present in atheroma in young persons with early atherosclerosis and to compare the findings in age- and sex-matched persons without atherosclerosis. A left anterior descending coronary artery sample, formalin-fixed, from 49 subjects, 15-34 years of age, from the multicenter study called Pathobiological Determinants of Atherosclerosis in Youth (PDAY), was examined by immunocytochemistry and the polymerase chain reaction (PCR) for the presence of C. pneumoniae and by PCR for cytomegalovirus. A hematoxylin/eosin-stained section was used to determine disease present in the studied sample. Seven of the artery samples were found to have atheromatous plaque, 11 had intimal thickening, and 31 had no lesions. Eight of the samples were positive for C. pneumoniae by immunocytochemistry (n = 7) and/or PCR (n = 3). Six of the 7 (86%) atheroma, 2 of the 11 (18%) with intimal thickening, and none of the 31 normal-appearing coronary samples were positive. Four were positive by PCR for cytomegalovirus, 2 from diseased arteries and 2 from normal arteries. Examination of the adjacent left coronary artery sample with a fat stain found abnormalities in 25 of the patients, but 19 still showed no evidence of atherosclerosis as a result of either examination. Thus, C. pneumoniae is found in coronary lesions in young adults with atherosclerosis but is not found in normal-appearing coronary arteries of both persons with and without other evidence of atherosclerosis.

Ischaemia and outcome with normal coronary arteries

This editorial refers to 'Long-term survival of patients with chest pain syndrome and angiographically normal or near-normal coronary arteries: the additional prognostic value of dipyridamole echocardiography test'dagger by R. Sicari et al., on page 2136.

Cardiac syndrome X: relevance of arterial pressure waveform analysis to patients with chest pain and normal coronary arteries

We report the case study of a 68-year-old female with cardiac syndrome X presenting with abnormal pressure waveforms and a hypertensive response to exercise with ST-segment depression. After amlodipine treatment, pressure waveform morphology was significantly improved, exercise testing was normal and symptoms had resolved. This case emphasizes the potential clinical value of arterial waveform analysis.