Prospective randomized trial comparing a nitinol self-expanding coronary stent with low-pressure dilatation and a high-pressure balloon expandable bare metal stent

Spontaneous coronary artery dissection: case report and literature review

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute myocardial infarction and sudden cardiac death. It occurs most commonly in otherwise healthy women during pregnancy or the postpartum period. The true incidence of SCAD is underestimated, as most cases are diagnosed at autopsy. The pathophysiology of SCAD is still not fully understood, and its management can be challenging. This report describes a 35-year-old pregnant female who presented with an acute antero-lateral ST elevation secondary to spontaneous dissection of the left anterior descending artery and the circumflex artery. The diagnosis was established by coronary artery angiography. However, the patient died following cardiac tamponade. The examination of this case represented a starting point for the reviewing of the diagnosis, clinical course, and management of SCAD, and for the placing of this in context with the existing literature. This study highlights the importance of prompt diagnosis and subsequent lifesaving treatment.

Mechanism of luminal patency of the self-expanding Sideguard sidebranch stent: evaluation by intravascular ultrasound and optical coherence tomography

BACKGROUND

The Cappella Sideguard (CS) sidebranch stent is a self-expanding, thin-strut, nitinol device with anatomic flaring at the sidebranch ostium designed to treat bifurcation lesions.

OBJECTIVE

To evaluate the mechanism of long-term lumen patency of the novel, self-expanding CS sidebranch stent compared with a balloon-expandable stent in the main vessel.

METHODS

We performed intravascular ultrasound postintervention and at follow-up in 24 CS stents and in 28 balloon-expandable drug-eluting stents deployed in the corresponding main vessel. Thirteen patients also had optical coherence tomography (OCT) at follow-up to evaluate neointimal hyperplasia and strut coverage.

RESULTS

CS stent area at the sidebranch carina increased significantly from 3.8 ± 1.2 mm(2) postintervention to 4.6 ± 1.2 mm(2) at follow-up (P < 0.001), resulting in no change in lumen area (3.8 ± 1.2 mm(2) to 3.7 ± 1.2 mm(2) , P = 0.72) despite a neointimal area at follow-up of 0.9 ± 0.8 mm(2) . Volumetric changes were similar, and the distribution of neointimal hyperplasia peaked 1-2 mm distal to the carina. Change of lumen volume inversely correlated to the neointimal volume (R = -0.48, P < 0.001), but correlated positively to the change in stent volume (R = 0.52, P < 0.0001). By OCT, most CS struts were covered (100% [98.9, 100]) at the bifurcation site, whereas 61% of floating DES struts that crossed the sidebranch were covered by smooth tissue with a similar texture compared with neointima.

CONCLUSION

Although neointimal hyperplasia accumulates within the CS stent mainly 1-2 mm distal to the carina, the self-expanding CS stent may be effective in maintaining an adequate patency in the sidebranch by continued stent expansion noted at follow-up.

Intravascular ultrasound comparison of the self-expanding Sideguard stent in the side branch versus a balloon-expandable stent in the main vessel to assess mechanisms of acute lumen gain in bifurcation lesions

OBJECTIVES

We compared the mechanisms of lumen gain after Cappella Sideguard (CS) side branch (SB) bifurcation stent deployment versus a balloon-expandable stent in the corresponding main vessel (MV).

BACKGROUND

The novel CS SB bifurcation stent is a self-expanding, thin-strut, nitinol device with anatomic flaring at the SB ostium.

METHODS

In 28 bifurcation lesions, intravascular ultrasound imaging of both the SB and the MV was performed both pre- and postintervention; vessel and lumen areas were measured every 1 mm over a 5 mm segment beginning at the carina.

RESULTS

Although minimum lumen area (MLA) within the distal 5 mm segment beginning at the carina increased from 2.8 ± 1.3 mm(2) to 3.8 ± 1.1 mm(2), P < 0.001, in the SB and from 3.4 ± 1.4 mm(2) to 6.0 ± 1.1 mm(2), P < 0.001, in the MV, stent expansion (minimum stent area/distal reference lumen area) was significantly less in the SB compared with the MV (77.8 ± 21.3% vs. 91.6 ± 18.4%, P = 0.02). Post stenting, the MLA site was located at the carina more frequently in the SB (85.7%) than in the MV (60.7%), P = 0.04. Plaque volume in the 5 mm proximal to carina in the MV tended to decrease, whereas plaque volume in the SB increased slightly with no change in overall plaque volume in the 5-mm-long segment distal to the carina in the MV, suggesting plaque shift from the proximal MV to the SB.

CONCLUSIONS

Acute CS lumen gain is less than the lumen gain of a balloon-expandable stent in the MV because of less aggressive acute expansion and/or the plaque shift from the proximal MV to the SB.

Fatigue life analysis and experimental verification of coronary stent

A computational and experimental method on biomechanics of stent is presented to analyze the stress distribution of different phases and evaluate the fatigue life according to Goodman criteria. As a result, the maximum stress and alternating stress were always located at the curvature area of rings, the fatigue bands in the experiment also verified the computation rationality. Matching between the numerical simulation and experimental results was satisfactory, which proved that the finite element analysis could provide theoretical evidence and help design and optimize the stent structure.

Elective coronary stent patients: preinterventional functional status and clinical-instrumental assessment

The functional status of ischemic heart disease (IHD) is currently assessed using the Seattle Angina Questionnaire (SAQ), a tool for monitoring and predicting the patient's prognosis. Illness perceptions (IP) are associated with IHD behavioral risk factors. The aim of the study was to find whether different IP, as evaluated by the IP Questionnaire (IPQr), can predict any of the features of the SAQ, i.e., to determine whether the SAQ is influenced and/or biased by illness perceptions. Moreover, whether New York Heart Association class and Ejection Fraction (EF%) are predictors of IHD severity measured as need of subsequent stenting procedures was also assessed. Eighty IHD patients eligible for percutaneous coronary intervention (PCI) and drug-eluting stent implant were asked to complete the IPQr and the SAQ. Laboratory analyses, echocardiography, and coronary diagnostic and interventional procedures were performed concurrently. Physical limitations of the SAQ are predicted by IPQr emotional representation. Ischemic heart disease functional status is regulated by illness perceptions and beliefs. Thus, some of the inferences drawn from the SAQ regarding IHD prognosis and even interventional indications may be biased and compromise the prognostic reliability of the SAQ information on physical function. This can also have consequences for therapeutic indications.

Effect of balloon inflation time on expansion of sirolimus-eluting stent

There is little information about the relationship between balloon inflation time and sirolimus-eluting stent (SES) expansion. In this randomized intravascular ultrasound (IVUS) study, 92 de novo lesions in native coronary arteries that underwent SES implantation were enrolled. Sirolimus-eluting stent was implanted using an inflation pressure of 14 atm. Stent balloon was gradually inflated until 14 atm in 10 s. In the short inflation group, it was deflated immediately after an image of the balloon inflated at 14 atm was taken. Stent balloon inflation lasted 60 s in the long inflation group. Intravascular ultrasound was then performed. The long balloon inflation resulted in a larger stent cross-sectional area (4.9 +/- 1.6 mm(2) vs 4.3 +/- 1.4 mm(2), P < 0.05) and expansion (71% +/- 13% vs 60% +/- 13%, P < 0.001) compared to the short balloon inflation, although stent expansion was relatively low in both groups. The relatively longer balloon inflation time using an inflation pressure of 14 atm results in better SES expansion. However, in the majority of lesions, adequate stent expansion is not achieved even using long balloon inflation, if it is inflated at 14 atm.

Spontaneous coronary artery dissection: a report of two atypical cases

Spontaneous coronary artery dissection is a rare pathology that has no exact incidence, etiology, pathogenesis and evolution in literature. We report two cases of two women with coronary artery dissection, uncommon clinical presentation of acute coronary syndrome and without identifiable risk factors. A review of the literature and the management of this condition are presented.

Different vascular response to concurrent implantation of sirolimus- and zotarolimus-eluting stents in the same vessel

Drug-eluting stents (DES) have become routine therapy in clinical practice because restenosis is significantly reduced in patients treated with these devices. New generations of DES bearing newer antiproliferative drugs have been developed. Sirolimus was the first antiproliferative drug eluted by a DES (SES) while zotarolimus represents a sirolimus-derived, newer antiproliferative drug borne by a different kind of DES (ZES). This report describes two cases of different vascular response to concurrent side by side implantation of SES and ZES in the same vessel and highlights significant early restenosis of ZES as compared with SES.

Myocardial salvage for ST-elevation myocardial infarction with terminal QRS distortion and restoration of brisk epicardial coronary flow

Recently, it has been reported that large infarcts associated with terminal QRS distortion (QRSDIS) on the admission electrocardiograms of patients with ST-elevation myocardial infarctions (STEMIs) may be caused by a failure to achieve thrombolysis in myocardial infarction (TIMI) grade 3 flow after primary percutaneous coronary intervention (PCI). However, the relationship between QRSDIS and final infarct size when TIMI grade 3 flow could be achieved by primary PCI is still unclear. Sixty-two consecutive patients with first anterior STEMI and who achieved TIMI grade 3 flow by primary PCI were classified into two groups according to the presence (Group A, n = 18) or absence (Group B, n = 44) of QRSDIS. Two weeks after the onset of acute myocardial infarction, Group A had a larger left ventricular (LV) end-systolic volume index (LVESVI) and a lower LV ejection fraction (LVEF) than Group B (LVESVI: 38 +/- 13 vs 31 +/- 12 ml/m(2), P = 0.025: LVEF: 42% +/- 10% vs 51% +/- 10%, P = 0.004). Through multivariate analysis, independent predictors of poor LV systolic function (LVEF < 40%) were determined to be the presence of QRSDIS (odds ratio 21.04, P = 0.021) and proximal left anterior descending artery occlusion (odds ratio 16.15, P = 0.033). Myocardial damage could not be reduced in patients experiencing STEMI with QRSDIS, even when TIMI grade 3 flow could be achieved by primary PCI, as much as in patients experiencing STEMI without QRSDIS.