Cardiophile MD » Angiography and Interventions

Polymer free amphilimus stent better than paclitaxel eluting stent?

Johnson Francis — Sat, 28 Jan 2012 01:35:55 +0000

Carrid D and colleagues [A Multicenter Randomized Trial Comparing Amphilimus- With Paclitaxel-Eluting Stents in De Novo Native Coronary Artery Lesions. J Am Coll Cardiol, doi:10.1016/j.jacc.2011.12.009 (Published online 25 January 2012)] from Europe have compared polymer free amphilimus eluting stents with permanent polymer coated paclitaxel eluting stents in percutaneous coronary interventions of de novo lesions. The primary end point was angiographic late lumen loss at six months. One fifth of the patients had also undergone intravascular ultrasound (IVUS) evaluation. The duration of clinical follow up was five years. Among the three hundred and twenty odd patients studied, the clinical end points of cardiac death, myocardial infarction, target vessel revascularization (TLR) and stent thrombosis was similar between the two groups at one year. In stent late lumen loss was lower with amphilimus stent (0.14 ± 0.36 mm vs. 0.34 ± 0.40 mm, with p for both noninferiority and superiority <0.0001). The authors claim that the polymer free amphilimus stent has a significantly lower in stent late lumen loss and a trend towards better one year clinical safety and efficacy in the treatment of de novo coronary lesions. The stent technology is based on polymer free abluminal reservoir elution which avoids the exposure of the vessel wall to polymers present in the luminal side of conventional drug eluting stents which are potentially proinflammatory and may impair the healing of the vessel. The authors also claim that this feature may potentially reduce the need for prolonged dual anti platelet therapy with its attendant complications. We need more large scale randomized head to head comparisons of the various new generation coronary stents to get the final answer on which is the better of the lot.

Role of PCI in CAD associated with severe aortic stenosis

Johnson Francis — Fri, 27 Jan 2012 07:21:26 +0000

Conventionally CAD (coronary artery disease) associated with severe aortic stenosis is an indication for coronary artery bypass grafting along with surgical aortic valve replacement. But in this era of transcatheter aortic valve replacement (TAVR; also known as transcatheter aortic valve implantation or TAVI), is there a role of PCI (percutaneous coronary intervention) in those awaiting TAVR? Goel SS and colleagues evaluated this aspect in a retrospective analysis of their PCI database. They could identify over two hundred and fifty patients with severe aortic stenosis who had undergone PCI for their associated CAD. They also identified over five hundred patients without aortic stenosis who had undergone PCI using propensity matching. The investigators concluded that percutaneous coronary intervention could be performed in those with severe symptomatic aortic stenosis and CAD with no significant increased risk of short term mortality compared to propensity matched patients without significant aortic stenosis. They also observed that patients with severe left ventricular dysfunction (ejection fraction thirty percent or less) and those with STS (Society of Thoracic Surgeons) score of 10 percent or more are at a highest risk of 30 day mortality after PCI. Online STS risk calculator is available at: http://riskcalc.sts.org/STSWebRiskCalc273/

Optical coherence tomography (OCT)

Johnson Francis — Sat, 21 Jan 2012 02:12:05 +0000

Optical coherence tomography (OCT) has much higher resolution compared to intravascular ultrasound. It has the resolution of the range of 10 20 microns, which is an order of magnitude better than that of intravascular ultrasound. But the limitation is the lower depth of tissue penetration which is only 2 to 3 millimeters, compared to the 10 millimeter tissue penetration of current intravascular ultrasound probes. Hence it has limitations while imaging large vessels like left main coronary artery and proximal left anterior descending coronary artery. The excellent resolution of optical coherence tomography is very useful in examining the coronary lesion characteristics like plaque rupture and also for monitoring the results of percutaneous interventions with stent deployment. OCT uses light waves instead of ultrasound for imaging. A light emitting source and system to collect the reflected light which checks the intensity of back scatter from internal microstructures with varying optical properties and the time delay of receiving the return signal are part of the OCT device. Since the speed of light is very much faster than that of sound, it is practically impossible to detect time delay of reflected waves electronically. A special device known as time domain OCT interferometer is used for this purpose. OCT is useful in plaque characterisatiion including the measurement of thickness of the fibrous cap which is an important determinant of plaque stability. The macrophage content of the plaque can also be estimated as the macrophages are of relatively large size (20 to 50 microns) and have a high degree of optical contrast. Hence plaques rich in macrophages have a high OCT signal variance. An excellent review on OCT is available at: Cardiac optical coherence tomography. Heart 2008;94:1200-1210, written by Raffel OC and colleagues, in the technology and guidelines section.

Ultrasonography for detecting radial access site complications

Johnson Francis — Wed, 18 Jan 2012 17:25:57 +0000

Uhlemann M et al have reported radial access site complications in their prospective vascular ultrasound registry [The Leipzig Prospective Vascular Ultrasound Registry in Radial Artery Catheterization. Impact of Sheath Size on Vascular Complications. J Am Coll Cardiol Intv, 2012; 5:36-43]. The primary objective of the study was to find the impact of sheath size on the chance of radial artery occlusion. They evaluated over four hundred and fifty patients between 2009 and 2010. Duplex ultrasound studies were done in all patients before discharge. Symptomatic radial artery occlusions were treated with low molecular weight heparin. Total access site vascular complication rate was 14.4 percent with a 5 F sheath and 33.1 percent with a 6 F sheath. Occlusion of the radial artery occurred in 13.7 percent with 5F sheaths and 30.5 percent with 6 F sheath. Other access site complications assessed in the study were hemorrhage, pseudoaneurysm, arteriovenous fistula. 42.5 percent of the radial artery occlusions were immediately symptomatic while seven percent became symptomatic within a mean of four days. Recanalization rates were higher in those who received low molecular weight heparin (55.6% vs. 13.5%, p < 0.001) after a mean period of 14 days. The incidence of radial artery occlusions noted by ultra sound evaluation in this study was surprisingly high, more so in those whom a larger sheath had been deployed.

Study supporting trans radial access for primary angioplasty

Johnson Francis — Tue, 17 Jan 2012 17:33:26 +0000

Trans radial vascular access is gaining popularity for both elective and primary angioplasty in acute myocardial infarction. It is well known that trans radial access has lower access site bleeding compared to trans femoral route. It is also equally well known that bleeding and consequent need for blood product transfusions can cause higher mortality in myocardial infarction patients undergoing percutaneous coronary intervention. In a retrospective analysis, Valgimigli M and associates from Italy have evaluated whether trans radial or trans femoral access is better for primary angioplasty in acute myocardial infarction [Transradial Versus Transfemoral Intervention for Acute Myocardial Infarction. A Propensity Score-Adjusted and -Matched Analysis From the REAL (REgistro regionale AngiopLastiche dell'Emilia-Romagna) Multicenter Registry. J Am Coll Cardiol Intv, 2012; 5:23-35]. Of a total of over eleven thousand patients who underwent primary percutaneous intervention for acute myocacardial infarction, eight thousand had trans femoral access while over three thousand had trans radial access. It was interesting to note that the two year risk adjusted mortality rates were lower for transradial than transfemoral route (8.8% vs. 11.4%; p = 0.0250). There was also a similar lower rate of vascular complications requiring surgery or needing blood transfusion in the trans radial group (1.1% vs. 2.5%, p = 0.0052).

MACE vs NACE in coronary interventions

Johnson Francis — Tue, 17 Jan 2012 06:37:54 +0000

MACE = major adverse cardiovascular event(s)

Components of MACE are death, reinfarction, ischemia-driven target vessel revascularization, and stroke.

NACE = net adverse clinical event(s); NACE = (MACE + major bleeding unrelated to coronary artery bypass grafting)

The term NACE was introduced in the HORIZONS Trial [Stone GW et al. Bivalirudin during primary PCI in acute myocardial infarction. N Engl J Med. 2008;358:2218–2230]

Supervised exercise vs primary stenting for claudication

Johnson Francis — Tue, 17 Jan 2012 05:11:22 +0000

The CLEVER Study [Murphy TP et al. Supervised Exercise Versus Primary Stenting for Claudication Resulting From Aortoiliac Peripheral Artery Disease. Six-Month Outcomes From the Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) Study. Circulation. 2012; 125: 130-139] assessed the efficacy of supervised exercise program in improving claudication in persons with aorto iliac peripheral artery disease. It was rather surprising to find that treadmill walking performance was better with supervised exercise program than with primary stenting in those with aortoiliac peripheral artery disease. But patient reported quality of life was better in the stenting group. This study involved one hundred and eleven patient with aortoiliac peripheral artery disease and were assigned to either optimal medical care, optimal medical care with supervised exercise or optimal medical care plus revascularization with stents. Walking Impairment Questionnaire and Peripheral Artery Questionnaire was used to assess disease specific quality of life.

Percutaneous mitral valve repair – EVEREST II – high risk study results

Johnson Francis — Thu, 05 Jan 2012 06:35:32 +0000

Mitral valve repair is conventionally the realm of cardiac surgeons. Recently the repair of the mitral valve in cases at high risk of surgery is being done with percutaneously deployed clips [MitraClip device (Abbott Vascular, Santa Clara, California)] to reduce the severity of mitral regurgitation. The EVEREST II – HRS (Endovascular Valve Edge-to-Edge Repair – High Risk Study) evaluated the safety and utility of this approach the acute and one year results are available [Whitlow PL et al. Acute and 12-Month Results With Catheter-Based Mitral Valve Leaflet Repair - The EVEREST II (Endovascular Valve Edge-to-Edge Repair) High Risk Study. J Am Coll Cardiol, 2012; 59:130-139]. Patients enrolled were those deemed high risk for a surgical repair of the mitral valve, with an estimated surgical mortality of twelve percent or above. Of the seventy eight patients who underwent the MitraClip procedure, more than half had a previous cardiac surgery and the mean age was seventy seven years. The thirty day procedure related mortality was 7.7 percent vs 8.3 percent mortality in the comparator group. The one year survival was seventy six percent, which was significantly better than the fifty five percent survival in the comparator group (p=0.047). Seventy eight percent of the survivors had grade 2 or less of mitral regurgitation at one year. The NYHA (New York Heart Association) functional class was also remarkably better from class III/IV in eighty nine percent at baseline to class I/II in seventy four percent (p<0.0001). Quality of life scores improved and hospitalizations were reduced. Significant reverse remodeling of the left ventricle was also noted at one year.

Minimizing vascular complications of percutaneous aortic valve replacement

Johnson Francis — Thu, 05 Jan 2012 04:59:02 +0000

Trancatheter aortic valve implantation (TAVI) or percutaneous aortic valve replacement is a fast developing modality for management of aortic stenosis, especially those unfit for surgical replacement. Though multiple approaches have been used, the most commonly used are the trans apical and transfemoral routes. Transfemoral route is a purely percutaneous technique and is becoming more popular. Due to the large diameters of the hardware, vascular access site complications are a concern with fully percutaneous aortic valve replacement. Toggweiler S and associates have tried to analyze the determinants of vascular complications in this setting and the improvement over time [Percutaneous Aortic Valve Replacement. Vascular Outcomes With a Fully Percutaneous Procedure. J Am Coll Cardiol, 2012; 59:113-118]. Over one hundred and thirty five patients underwent the procedure during 2009-2010. Planned arteriotomy closure with percutaneous pre-closure technique was use in all but one of the patients. Smaller sheaths, rigorous angiographic and computed tomographic (CT) screening and patient selection were used. They could achieve a reduction in major vascular complications from eight percent to one percent over this period. Minor vascular complication decrease from twenty four percent to eight percent. Major bleeds declined markedly from fourteen percent to just one percent (p<0.01). They noted that complications were more likely if the minimal diameter of the artery was smaller than the external sheath diameter. This was more so if the there was peripheral vascular disease and moderate or severe vascular calcification.

Late and very late stent thrombosis with drug eluting stents

Johnson Francis — Wed, 28 Dec 2011 01:01:35 +0000

Late and very late stent thrombosis with drug eluting stents still continue to be our concern. Fresh data from the jCypher registry is available from Kimura T and associates [Very Late Stent Thrombosis and Late Target Lesion Revascularization after Sirolimus-Eluting Stent Implantation: Five-year Outcome of the j-Cypher Registry. CIRCULATIONAHA.111.046599. Published online before print December 27, 2011, doi: 10.1161/?CIRCULATIONAHA.111.046599]. In this group of over twelve thousand and eight hundred patients undergoing sirolimus eluting stent implanation, the one month stent thrombosis was 0.3% while the one year cumulative stent thrombosis rate was 0.6%. Five year cumulative stent thrombosis rate was 1.6%. Acute coronary syndrome and proximal left anterior descending coronary artery were risk factors for early stent thrombosis. Side branch stenting, diabetes mellitus and end stage renal disease with or without hemodialysis were risk factors for late stent thrombosis. Current smoking and total stent length more than twenty eight millimeters were risk factors for very late stent thrombosis. Early stent thrombosis was calculated at thirty days, late stent thrombosis at one year and very late stent thrombosis at five years. Late and very late stent thrombosis rates were calculated at 0.26% per year. Target vessel revascularization (TLR) within first year was low at 7.35%. Beyond one year, it continued at a rate of 2.2% per year upto five years.