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| __NOTOC__
| | #Redirect [[Coronary artery calcification#Treatment]] |
| {{PCI}}
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| {{CMG}}; '''Associate Editor(s)-In-Chief:''' Thomas Tu, M.D.; Brian C. Bigelow, M.D.
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| ==Overview==
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| [[calcification|Calcified]] [[lesion]]s pose several challenges to the [[interventional cardiologist]]s as they are sometimes difficult to cross with the [[angioplasty]] equipment, they are less likely to fully dilate, they are prone to recoil, and they often do not allow for full expansion of the [[stent]]. Failure to fully expand the [[stent]] may result in [[restenosis]]. [[Rotational atherectomy]] is frequently employed following unsuccessful pre-dilating PTCA to perform [[plaque]] modification. [[Stents]] should be deployed only after ensuring that the [[lesion]] can be fully expanded by a conventional balloon [[angioplasty]].
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| ==Diagnosis of Lesion Calcification==
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| The coronary angiogram is fairly insensitive to the presence of lesion calcification, particularly the presence of deep vessel wall calcification. [[Intravascular ultrasound]] is much more sensitive sensitive in the assessment of vessel wall calcification. 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> Calcification of [[SVG|SVGs]] is generally within the reference [[vessel wall]] rather than within the lesion itself. Calcification is 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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| ==Complications and Technical Challenges Associated with Calcified Lesions ==
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| ===Reduced Compliance of the Vessel===
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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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| ===Reduced Ability to Cross the Lesion===
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| * The lack of flexibility in calcified arteries makes it difficult to advance balloons and particularly stents down a tortuous vessel. This is often observed in a tortuous and calcified right coronary artery.
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| * The presence of coronary [[calcification]] also reduces the ability to cross chronic total [[occlusion|occlusions]] and severely stenotic lesions.
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| ===Reduced Ability to Fully Dilate the Lesion===
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| * Stent strut expansion is inversely correlated with the circumferential arc of calcium on intravascular ultrasound. <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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| * Extensive coronary [[calcification]] is associated with muscle rigidity requiring higher [[balloon]] inflation pressures to obtain complete stent expansion.
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| == Treatment ==
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| ===Guidewire Technique===
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| Often times hydrophilic [[guidewires]] with a core that extends to the tip are necessary to cross heavily calcified lesions. Once the lesion is crossed, then a more flexible and less traumatic wire can be inserted distally to minimize vessel, and to minimize the potential for [[vessel perforation]]. If there is the difficulty in delivering the equipment, then a more rigid wire such as a [[stabilizer wire]] can be used to facilitate passage of devices. Sometimes two wires are used in the "buddy wire technique" to straighten the vessel and facilitate delivery of devices.
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| ===Balloon Dilation===
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| 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 an 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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| Caution should be used in the patient with a low ejection fraction as distal embolization from rotational atherectomy can result in a decline and LV function. Also, tortuous segments with acute bends should not be treated with rotational atherectomy is there is an increased risk of vessel [[dissection]] at the site of acute bends and turns.
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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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| ==2011 ACCF/AHA/SCAI Guidelines for Percutaneous Coronary Intervention (DO NOT EDIT)<ref name="pmid22070837">{{cite journal |author=Levine GN, Bates ER, Blankenship JC, Bailey SR, Bittl JA, Cercek B, Chambers CE, Ellis SG, Guyton RA, Hollenberg SM, Khot UN, Lange RA, Mauri L, Mehran R, Moussa ID, Mukherjee D, Nallamothu BK, Ting HH |title=2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention: Executive Summary A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions |journal=[[Journal of the American College of Cardiology]] |volume=58 |issue=24|pages=2550–83 |year=2011 |month=December|pmid=22070837 |doi=10.1016/j.jacc.2011.08.006|url=http://linkinghub.elsevier.com/retrieve/pii/S0735-1097(11)02875-0|accessdate=2011-12-08|url=http://content.onlinejacc.org/cgi/reprint/58/24/2550.pdf|PDF}}</ref>==
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| ===Calcified Lesions (DO NOT EDIT)<ref name="pmid22070837">{{cite journal|author=Levine GN, Bates ER, Blankenship JC, Bailey SR, Bittl JA, Cercek B, Chambers CE, Ellis SG, Guyton RA, Hollenberg SM, Khot UN, Lange RA, Mauri L, Mehran R, Moussa ID, Mukherjee D, Nallamothu BK, Ting HH |title=2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention: Executive Summary A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions |journal=[[Journal of the American College of Cardiology]]|volume=58 |issue=24 |pages=2550–83 |year=2011|month=December|pmid=22070837|doi=10.1016/j.jacc.2011.08.006|url=http://linkinghub.elsevier.com/retrieve/pii/S0735-1097(11)02875-0|accessdate=2011-12-08|url=http://content.onlinejacc.org/cgi/reprint/58/24/2550.pdf|PDF}}</ref>===
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| {|class="wikitable"
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| | colspan="1" style="text-align:center; background:LemonChiffon"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class IIa]]
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| |bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' [[PCI in the calcified lesion#Rotational Atherectomy|Rotational atherectomy]] is reasonable for fibrotic or heavily calcified lesions that might not be crossed by a [[PCI in the calcified lesion#Balloon Dilation|balloon catheter]] or adequately dilated before [[PCI in the calcified lesion#Stents|stent implantation]].<ref name="pmid9236427">{{cite journal |author=Moussa I, Di Mario C, Moses J, Reimers B, Di Francesco L, Martini G, Tobis J, Colombo A|title=Coronary stenting after rotational atherectomy in calcified and complex lesions. Angiographic and clinical follow-up results|journal=[[Circulation]] |volume=96 |issue=1 |pages=128–36 |year=1997 |month=July |pmid=9236427 |doi=|url=http://circ.ahajournals.org/cgi/pmidlookup?view=long&pmid=9236427 |accessdate=2011-12-15}}</ref><ref name="pmid20636844">{{cite journal|author=Vaquerizo B, Serra A, Miranda F, Triano JL, Sierra G, Delgado G, Puentes A, Mojal S, Brugera J |title=Aggressive plaque modification with rotational atherectomy and/or cutting balloon before drug-eluting stent implantation for the treatment of calcified coronary lesions|journal=[[Journal of Interventional Cardiology]] |volume=23 |issue=3 |pages=240–8 |year=2010 |month=June |pmid=20636844|doi=10.1111/j.1540-8183.2010.00547.x |url=http://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0896-4327&date=2010&volume=23&issue=3&spage=240 |accessdate=2011-12-15}}</ref><ref name="pmid8456756">{{cite journal |author=Brogan WC, Popma JJ, Pichard AD, Satler LF, Kent KM, Mintz GS, Leon MB |title=Rotational coronary atherectomy after unsuccessful coronary balloon angioplasty |journal=[[The American Journal of Cardiology]] |volume=71 |issue=10 |pages=794–8 |year=1993|month=April |pmid=8456756 |doi= |url= |accessdate=2011-12-15}}</ref> ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
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| ==References==
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| {{Reflist|2}}
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