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| {{SI}}
| | #Redirect [[Coronary artery calcification#Treatment]] |
| {{WikiDoc Cardiology Network Infobox}}
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| {{CMG}}<br/>
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| '''Associate Editors-In-Chief:''' John N. Mafi, M.D.; Randall K. Harada, M.D.; Thomas Tu, M.D.; Brian C. Bigelow, M.D.
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| {{Editor Help}}
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| == Challenges of Calcified Lesions ==
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| * Heavily calcified lesions add complexity to a [[percutaneous coronary intervention]].
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| * The presence of coronary [[calcification]] reduces the compliance of the vessel, and it may predispose calcified plaque–normal wall interfaces to [[dissections]] after [[balloon angioplasty]].
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| * The presence of coronary [[calcification]] also reduces the ability to cross chronic total [[occlusion|occlusions]]. In severely calcified lesions, stent strut expansion is inversely correlated with the circumferential arc of calcium. <ref name="pmid11170322">{{cite journal |author=Vavuranakis M, Toutouzas K, Stefanadis C, Chrisohou C, Markou D, Toutouzas P |title=Stent deployment in calcified lesions: can we overcome calcific restraint with high-pressure balloon inflations? |journal=Catheter Cardiovasc Interv |volume=52 |issue=2 |pages=164–72 |year=2001 |month=February |pmid=11170322 |doi= |url=}}</ref>
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| * The presence of extensive coronary [[calcification]] poses unique challenges for PCI as [[calcium]] in the vessel wall leads to irregular and inflexible [[Lumen (anatomy)|lumens]]. It also makes the delivery of guidewires, [[balloons]], and [[stents]] much more challenging.
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| * Extensive coronary [[calcification]] also renders the [[vessel]] wall rigid, necessitating higher [[balloon]] inflation pressures to obtain complete stent expansion, and occasionally leading to “undilatable” lesions that resist any achievable [[balloon]] expansion pressure.
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| '''Calcification in Saphenous Vein Grafts (SVGs)'''
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| Calcification noted within [[SVG|SVGs]] are generally within the reference [[vessel wall]] rather than within the lesion, and they are often associated with older graft age, [[insulin–dependent diabetics]], and [[smoking]]. <ref name="pmid15723972">{{cite journal |author=Castagna MT, Mintz GS, Ohlmann P, ''et al.'' |title=Incidence, location, magnitude, and clinical correlates of [[saphenous vein graft]] [[calcification]]: an intravascular [[ultrasound]] and [[angiographic]] study |journal=Circulation |volume=111 |issue=9 |pages=1148–52 |year=2005 |month=March |pmid=15723972 |doi=10.1161/01.CIR.0000157160.69812.55 |url=}}</ref>
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| == Angiographic Evaluation ==
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| Coronary artery [[calcium]] is an important marker for coronary [[atherosclerosis]]. Conventional coronary [[angiography]] has limited [[sensitivity]] for the detection of smaller amounts of [[calcium]], and has moderate [[sensitivity]] for the detection of extensive lesion [[calcium]] (sensitivity 60% and 85% for three- and four-quadrant calcium, respectively). <ref name="pmid7895353">{{cite journal |author=Mintz GS, Popma JJ, Pichard AD, ''et al.'' |title=Patterns of calcification in coronary artery disease. A statistical analysis of intravascular ultrasound and coronary angiography in 1155 lesions |journal=Circulation |volume=91 |issue=7 |pages=1959–65 |year=1995 |month=April |pmid=7895353 |doi= |url=}}</ref> | |
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| == Treatment ==
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| There are a variety of diagnostic and treatment options for calcified lesions. Better early outcomes may be achieved by using a multi-device interventional strategy.
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| ===Percutaneous Transluminal Coronary Angioplasty (PTCA)===
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| [[PTCA]] is an invasive [[Cardiology|cardiologic]] therapeutic procedure to treat the [[stenosis|stenotic]] (narrowed) [[coronary artery|coronary arteries]] of the [[heart]]. The term [[balloon angioplasty]] is commonly used to describe this procedure, which describes the inflation of a [[balloon]] within the [[coronary artery]] to crush the plaque into the walls of the artery.
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| In the treatment of calcified lesions with PTCA, certain considerations must be made. For one, [[Interventional cardiologist|interventional cardiologists]] should consider using [[hydrophilic]] guidewires, as heavy [[calcification]] may make wire advancement difficult. Also, calcified [[plaque|plaques]] usually require higher [[balloon]] pressures to fully expand than normal [[plaque|plaques]]. Because of this, [[Compliance|non-compliant]] [[balloons]] may be a better choice than [[Compliance|compliant]] or [[Compliance|semi-compliant]] [[balloons]]. Differential expansion of compliant or semi-compliant [[balloons]] inside a particular [[lesion]] may jeopardize less diseased segments if the [[balloon]] expands greater than the vessel's native diameter. On the contrary, non-compliant [[balloons]] allow for a more uniform expansion at high pressures and therefore may be a better choice to apply focused pressure at the calcified [[plaque]]. Another option is to place a second "buddy" wire adjacent to the [[balloon]] to improve the ability to dilate calcified [[plaque]].
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| If pre-dilatation fails to fully expand a calcified [[stenosis]], then the risks and benefits of stent deployment should be carefully considered due to the risk of incomplete expansion and future [[restenosis]].
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| ===Intravascular Ultrasound (IVUS)===
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| [[IVUS]] is a [[medical imaging]] methodology that uses a specially designed [[catheter]] with a miniaturized [[ultrasound]] probe attached to the distal end of the [[catheter]]. The proximal end of the [[catheter]] is attached to computerized [[ultrasound]] equipment. It allows the application of [[ultrasound]] technology to see from inside [[blood vessel|blood vessels]] out through the surrounding [[blood]] column, visualizing the [[endothelium]] (inner wall) of [[blood vessel|blood vessels]] in living individuals. IVUS is used in the coronary arteries to determine the amount of [[atheroma|atheromatous plaque]] built up at any particular point in the epicardial coronary artery.
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| While coronary angiography by [[fluroscopy]] is limited in its detection and severity assessment of coronary calcification, IVUS can assess the extent of calcification and may be particularly useful for instances when the reason for poor [[balloon]] expansion is uncertain. Although this approach has its advantages over angiography, heavy involvement of superficial, sub-endothelial [[calcification]] may require [[rotational atherectomy]].
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| ===Cutting Balloon and FX MiniRailTM===
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| A [[cutting balloon]] is an [[angioplasty]] device used in [[PCI|percutaneous coronary interventions]]. It has a special [[balloon]] tip with small blades, that are activated when the [[balloon]] is inflated. This procedure is different from [[rotational atherectomy]], in which a diamond tipped device spins at high revolutions to cut away calcific (chalky) [[atheroma]] usually prior to coronary [[stenting]].
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| This technique can be useful in treating calcified lesions because the microsurgical blades on the surface of the [[balloon]] may help to score and modify calcified [[plaques]]. Generally, if a [[cutting balloon]] will cross the lesion, a [[stent]] can be delivered. Although this technique has its advantages, there are certain additional considerations that must be made before deciding to use this procedure. For one, despite their usefulness, these [[balloons]] are often more difficult to deliver past tortuous or calcified segments, so extra care must be used. Also, there were no significant differences observed in rates of [[restenosis]] when using this procedure.
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| ===Rotational Atherectomy===
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| [[Rotational atherectomy]] is a minimally invasive method of removing [[plaque]] and blockages from an [[artery]] and subsequently widening arteries that have been narrowed by arterial disease. Unlike [[angioplasty]] and [[stents]] of blocked arteries that simply push blockages aside into the wall of the artery, rotational atherectomy involves inserting a thin catheter with a rotating blade on its end into the artery. The rotating edge is used to remove [[plaque]] buildups, thereby opening the [[artery]] and restoring normal blood flow.
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| [[Rotational atherectomy]] is frequently employed following unsuccessful pre-dilating [[PTCA]] to perform [[plaque]] modification. This procedure facilitates [[Percutaneous transluminal coronary angioplasty|PTCA]] by creating micro-fractures, removing calcified plaque, and increasing vessel compliance. Despite its usefulness in treating calcified lesions, certain precautions should be taken. In an effort to limit the risk of vessel [[laceration]], smaller diameter [[Burr (cutter)|burrs]] are now preferred. A general guideline to use is that the initial [[Burr (cutter)|burr]] to [[Lumen (anatomy)|luminal]] ratio should be 1:2. Additional caution should be taken when a coronary [[dissection]] is present, as [[rotational atherectomy]] may propagate the [[dissection]].
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| * '''Rotational atherectomy in severe lesion calcification:''' [[Rotational atherectomy]] is the preferred pretreatment method in patients with severe lesion [[calcification]], particularly ostial lesions, and facilitates the delivery and expansion of coronary [[stents]] by creating microdissection planes within the fibrocalcific [[plaque]]. Yet even with these contemporary methods, the presence of moderate or severe coronary calcification is associated with reduced procedural success and higher complication rates<ref name="pmid12127606">{{cite journal |author=Wilensky RL, Selzer F, Johnston J, ''et al.'' |title=Relation of percutaneous coronary intervention of complex lesions to clinical outcomes (from the NHLBI Dynamic Registry) |journal=Am. J. Cardiol. |volume=90 |issue=3 |pages=216–21 |year=2002 |month=August |pmid=12127606 |doi= |url=}}</ref>, including stent dislodgement.
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| * '''Rotational atherectomy in mild-moderate calcifications:''' In less severely calcified lesions, no differences in [[restenosis]] rates were found after paclitaxel-eluting stent implantation in calcified and non-calcified vessels. <ref name="pmid16253590">{{cite journal |author=Moussa I, Ellis SG, Jones M, ''et al.'' |title=Impact of coronary culprit lesion calcium in patients undergoing paclitaxel-eluting stent implantation (a TAXUS-IV sub study) |journal=Am. J. Cardiol. |volume=96 |issue=9 |pages=1242–7 |year=2005 |month=November |pmid=16253590 |doi=10.1016/j.amjcard.2005.06.064 |url=}}</ref>
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| ===Directional Coronary Atherectomy (DCA)===
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| DCA involves inserting a thin, flexible [[catheter]] with a small blade on its end into the artery, which cuts off [[plaque]] buildups. These [[plaque]] shavings are caught with the catheter and are subsequently removed from the artery.<ref>http://www.lvhn.org/lvh/Your_LVH/Health_Care_Services/Heart_Care_MIMS/Most_Advanced_Treatments|3487</ref>
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| One problem that may arise during the procedure is that heavy [[calcification]] proximal to the target lesion may limit deliverability of the device and its success.
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| ===Excimer Laser Coronary Atherectomy/Angioplasty (ECLA)===
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| ECLA uses a laser, instead of a traditional blade, to perform [[atherectomy]] and [[angioplasty]]. The excimer laser is a pulsed [[ultraviolet]] laser that can erode calcified [[plaque]] while also causing minimal thermal tissue injury.<ref name="pmid1860207">{{cite journal |author=Cook SL, Eigler NL, Shefer A, Goldenberg T, Forrester JS, Litvack F |title=Percutaneous excimer laser coronary angioplasty of lesions not ideal for balloon angioplasty |journal=Circulation |volume=84 |issue=2 |pages=632–43 |year=1991 |month=August |pmid=1860207 |doi= |url=}}</ref>
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| One advantage of using ELCA is that it fractures calcified [[plaques]], thereby facilitating [[PTCA]]. However, it also has a higher equipment cost and has a lesser ease of use than [[rotational atherectomy]]. Furthermore, it is more commonly used in lower extremity [[peripheral arterial disease]] than in [[CAD|coronary artery disease (CAD)]].
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| ===Stents===
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| In [[cardiology]], a [[stent]] is a tube that is inserted into an artery to counteract significant decreases in vessel diameter by acutely propping it open.
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| In the treatment of calcified [[lesions]], [[stents]] are frequently used in conjunction with [[PTCA]] or [[atherectomy]] to decrease the risk of [[restenosis]]. Extra care should be taken in deploying stents in lesions where incomplete expansion occurs following pre-dilation, as incomplete expansion of a target lesion will increase the likelihood of [[restenosis]]. [[Stents]] should be deployed only after ensuring full [[balloon]] expansion.
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| ==Summary==
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| In summary, heavily [[calcified]] lesions add complexity to a [[percutaneous coronary intervention]]. Other major points to remember include:
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| * Incomplete expansion of a target lesion will increase the likelihood of [[restenosis]].
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| * [[Rotational atherectomy]] is frequently employed following unsuccessful pre-dilating [[PTCA]] to perform plaque modification.
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| * [[Stents]] should be deployed only after ensuring full balloon expansion.
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| ==References==
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| <references/>
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| [[Category:Cardiology]]
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