Pocket Medicine

CARDIOLOGY

CORONARY ANGIOGRAPHY AND REVASCULARIZATION

Indications for coronary angiography in stable CAD or asx Pts

•  CCS class III–IV angina despite medical Rx or angina + systolic dysfxn

•  High-risk stress test findings (see prior topic)

•  Uncertain dx after noninvasive testing (& compelling need to determine dx), occupational need for definitive dx (eg, pilot) or inability to undergo noninvasive testing

•  Systolic dysfxn with unexplained cause

•  Survivor of SCD, polymorphic VT, sustained monomorphic VT

•  Suspected spasm or nonatherosclerotic cause of ischemia (eg, anomalous coronary)

Precath checklist

•  Document peripheral arterial exam (radial, femoral, DP, PT pulses; bruits); NPO >6 h

•  ✓ CBC, PT, & Cr; give IVF (± bicarb, ± acetylcysteine; see “CIAKI”); blood bank sample

•  ASA 325 mg × 1; consider clopi 600 mg ≥2–6 h before PCI or, if ACS, ticagrelor pre- or peri-PCI or prasugrel peri-PCI; cangrelor (IV P2Y12 inhib) ↓ peri-PCI ischemic events vs. clopi w/o preload (NEJM 2013;368:1303); consider statin preRx (Circ 2011;123:1622)

Coronary revascularization in stable CAD (Circ 2011;124:e574)

•  Optimal med Rx (OMT) should be initial focus if stable, w/o critical anatomy, & w/o ↓ EF

•  PCI: ↓ angina more quickly c/w OMT; does not ↓ D/MI (NEJM 2007;356:1503); in Pts w/ ≥1 stenosis w/ FFR ≤0.8 (see below), ↓ urg revasc c/w OMT (NEJM 2012;367:991); may be noninferior to CABG in unprotected left main dis. (NEJM 2011;364:1718)

•  CABG: in older studies, ↓ mort. c/w OMT if 3VD, LM, 2VD w/ critical prox LAD, esp. if ↓ EF; more recently, if EF <35% ↓ CV death vs. OMT (NEJM 2011;364:1607) insufficient evidence to support routine viability assessment (NEJM 2011;364:1617) in diabetics w/ ≥2VD, ↓ D/MI, but ↑ stroke c/w PCI (NEJM 2012;367:2375)

•  If revasc deemed necessary, PCI if limited # of discrete lesions, nl EF, no DM, poor operative candidate; CABG if extensive or diffuse disease, ↓ EF, DM or valvular disease; if 3VD/LM: CABG ↓ D/MI & revasc but trend toward ↑ stroke c/w PCI (Lancet 2013;381:629); SYNTAX score II helps identify Pts who benefit most from CABG (Lancet 2013;381:639)

PCI

•  Balloon angioplasty (POBA): effective, but c/b dissection & elastic recoil & neointimal hyperplasia → restenosis; now reserved for small lesions & ? some SVG lesions

•  Bare metal stents (BMS): ↓ elastic recoil → 33–50% ↓ restenosis & repeat revasc (to ~10% by 1 y) c/w POBA; requires ASA lifelong & P2Y12 inhib × ≥4 wk

•  Drug-eluting stents (DES): ↓ neointimal hyperplasia → ~75% ↓ restenosis, ~50% ↓ repeat revasc (to <5% by 1 y), no ↑ D/MI c/w BMS (NEJM 2013;368:254); next generation DES may ↓ repeat revasc & stent thrombosis; require P2Y12 inhib ≥1 y (Circ 2007;115:813)

•  Radial access ↓ vasc. complic. vs. femoral, but no ∆ D/MI/CVA (Lancet 2011;377:1409)

•  Fractional flow reserve [FFR; ratio of max flow (induced by IV or IC adenosine) distal vs. proximal to a stenosis] guided PCI (<0.8) → ↓ # stents & ↓ D/MI/revasc (NEJM 2009;360:213)

Post-PCI complications

•  Postprocedure ✓ vascular access site, distal pulses, ECG, CBC, Cr

•  Bleeding

hematoma/overt bleeding: manual compression, reverse/stop anticoag

retroperitoneal bleed: may p/w ↓ Hct ± back pain; ↑ HR & ↓ BP late; Dx w/ abd/pelvic CT (I); Rx: reverse/stop anticoag (d/w interventionalist), IVF/PRBC/plts as required

if bleeding uncontrolled, consult performing interventionalist or surgery

•  Vascular damage (~1% of dx angio, ~5% of PCI; Circ 2007;115:2666)

pseudoaneurysm: triad of pain, expansile mass, systolic bruit; Dx: U/S; Rx (if pain or >2 cm): manual or U/S-directed compression, thrombin injection or surgical repair

AV fistula: continuous bruit; Dx: U/S; Rx: surgical repair

LE ischemia (emboli, dissection, clot): cool, mottled extremity, ↓ distal pulses; Dx: pulse volume recording (PVR), angio; Rx: percutaneous or surgical repair

•  Peri-PCI MI: >5× ULN of Tn/CK-MB + either sx or ECG/angio Δs; Qw MI in <1%

•  Renal failure: contrast-induced manifests w/in 24 h, peaks 3–5 d (see “CIAKI”)

•  Cholesterol emboli syndrome (typically in middle-aged & elderly and w/ Ao atheroma)

renal failure (late and progressive, eos in urine); mesenteric ischemia (abd pain, LGIB, pancreatitis); intact distal pulses but livedo pattern and toe necrosis

•  Stent thrombosis: mins to yrs after PCI, typically p/w AMI. Due to mech prob. (stent underexpansion or unrecognized dissection, typically presents early) or d/c of antiplt Rx (esp. if d/c both ASA & P2Y12 inhib; JAMA 2005;293:2126). Risk of late stent thrombosis may be higher with DES than BMS ( JACC 2006;48:2584).

•  In-stent restenosis: mos after PCI, typically p/w gradual ↑ angina (10% p/w ACS). Due to combination of elastic recoil and neointimal hyperplasia; ↓ w/ DES vs. BMS.