- Bright blood: +/- gadolinium
- Dark blood (no contrast)
- Phase contrast for flow (no contrast)
- MRangiography (+/- contrast)
2. NSF: nephrogenic systemic fibrosis.
- Gadolinium given to patients in ESRD who can't clear it, contrast accumulates in skin and can cause fibrosis/strictures/contractures in joint and skin or excess laxity.
- No treatment. Only thing is prevention - do not give to anyone with GFR<30. If you dialyze them right after, the first dialysis takes them off 50%, second dialysis to 96%. However there is no change in the rate of development of NSF if you dialyze them. If their GFR is 30-60, and they're on dialysis, the recommendation is to reduce the gadolinium dose and dialyze them twice afterwards.
3. High signal on T1- fat, melanin (ie melanoma)
- High signal on T2- fluid
4. Viability imaging: images acquired 10 minutes after contrast injection. Assess the degree of damage and to what extent it can be recovered with revascularization interventions.
- Normal myocardium: wash in wash out
- ischemic myocardium: wash in slower (stenotic vessels), still wash out normally
- Infarcted myocardium: contrast washes in slow, and does not wash out, contrast becomes trapped inside
- If the infarcted wall is <50% of the total thickness of the heart muscle, then there is enough tissue left for revascularization to be successful. If its >50%, there is not enough tissue left over for revascularization to be successful. See following study in NEJM:
N Engl J Med. 2000 Nov 16;343(20):1445-53.
The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction.
BACKGROUND:
Recent studies indicate that magnetic resonance imaging (MRI) after the administration of contrast material can be used to distinguish between reversible and irreversible myocardial ischemic injury regardless of the extent of wall motion or the age of the infarct. We hypothesized that the results of contrast-enhanced MRI can be used to predict whether regions of abnormal ventricular contraction will improve after revascularization in patients with coronary artery disease.
METHODS:
Gadolinium-enhanced MRI was performed in 50 patients with ventricular dysfunction before they underwent surgical or percutaneous revascularization. The transmural extent of hyperenhanced regions was postulated to represent the transmural extent of nonviable myocardium. The extent of regional contractility at the same locations was determined by cine MRI before and after revascularization in 41 patients.
RESULTS:
Contrast-enhanced MRI showed hyperenhancement of myocardial tissue in 40 of 50 patients before revascularization. In all patients with hyperenhancement the difference in image intensity between hyperenhanced regions and regions without hyperenhancement was more than 6 SD. Before revascularization, 804 of the 2093 myocardial segments analyzed (38 percent) had abnormal contractility, and 694 segments (33 percent) had some areas of hyperenhancement. In an analysis of all 804 dysfunctional segments, the likelihood of improvement in regional contractility after revascularization decreased progressively as the transmural extent of hyperenhancement before revascularization increased (P<0.001). For instance, contractility increased in 256 of 329 segments (78 percent) with no hyperenhancement before revascularization, but in only 1 of 58 segments with hyperenhancement of more than 75 percent of tissue. The percentage of the left ventricle that was both dysfunctional and not hyperenhanced before revascularization was strongly related to the degree of improvement in the global mean wall-motion score (P<0.001) and the ejection fraction (P<0.001) after revascularization.
CONCLUSIONS:
Reversible myocardial dysfunction can be identified by contrast-enhanced MRI before coronary revascularization.
5. Takosubo stress-induced cardiomyopathy: physical or psychological stressor leading to acute MI picture (elevated troponins, wall motion abormalities, clinical symptoms) in the setting of normal coronaries. Perhaps some people are more sensitive to this, may have to do with variable AChR in the myocardial tissues.
6. Stress perfusion studies- Vasodilate, inject gadolinium, first pass (stress image)
- Do it again later (rest image)
- Comparing the two, you can identify reversible damage/potential ischemia in times of stress.
- Adenosine: potent vasodilator
7. No reflow phenonmonon
- Microvascular disease, small vessels are damaged too
- Gadolinium is unable to reach certain part of tissue
- Implies MI within last 7 days, poor prognostic indicator as even the small vessels are affected.
8. TAVR vs open aortic valve repair: PARTNER trial 20% reduction in mortality and improved QoL compared to medical therapy alone.
N Engl J Med. 2010 Oct 21;363(17):1597-607. doi: 10.1056/NEJMoa1008232. Epub 2010 Sep 22.
Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery.
Leon MB1, Smith CR, Mack M, Miller DC, Moses JW, Svensson LG, Tuzcu EM, Webb JG, Fontana GP, Makkar RR, Brown DL, Block PC, Guyton RA, Pichard AD, Bavaria JE, Herrmann HC, Douglas PS, Petersen JL, Akin JJ, Anderson WN, Wang D, Pocock S; PARTNER Trial Investigators.
BACKGROUND:
Many patients with severe aortic stenosis and coexisting conditions are not candidates for surgical replacement of the aortic valve. Recently, transcatheter aortic-valve implantation (TAVI) has been suggested as a less invasive treatment for high-risk patients with aortic stenosis.
METHODS:
We randomly assigned patients with severe aortic stenosis, whom surgeons considered not to be suitable candidates for surgery, to standard therapy (including balloon aortic valvuloplasty) or transfemoral transcatheter implantation of a balloon-expandable bovine pericardial valve. The primary end point was the rate of death from any cause.
RESULTS:
A total of 358 patients with aortic stenosis who were not considered to be suitable candidates for surgery underwent randomization at 21 centers (17 in the United States). At 1 year, the rate of death from any cause (Kaplan–Meier analysis) was 30.7% with TAVI, as compared with 50.7% with standard therapy (hazard ratio with TAVI, 0.55; 95% confidence interval [CI], 0.40 to 0.74; P<0.001). The rate of the composite end point of death from any cause or repeat hospitalization was 42.5% with TAVI as compared with 71.6% with standard therapy (hazard ratio, 0.46; 95% CI, 0.35 to 0.59; P<0.001). Among survivors at 1 year, the rate of cardiac symptoms (New York Heart Association class III or IV) was lower amongpatients who had undergone TAVI than among those who had received standard therapy (25.2% vs. 58.0%, P<0.001). At 30 days, TAVI, as compared with standard therapy, was associated with a higher incidence of major strokes (5.0% vs. 1.1%, P=0.06) and major vascular complications (16.2% vs. 1.1%, P<0.001). In the year after TAVI, there was no deterioration in the functioning of the bioprosthetic valve, as assessed by evidence of stenosis or regurgitation on an echocardiogram.
CONCLUSIONS:
In patients with severe aortic stenosis who were not suitable candidates for surgery, TAVI, as compared with standard therapy, significantly reduced the rates of death from any cause, the composite end point of death from any cause or repeat hospitalization, and cardiac symptoms, despite the higher incidence of major strokes and major vascular events. (Funded by Edwards Lifesciences; ClinicalTrials.gov number, NCT00530894.).
JACC Cardiovasc Interv. 2013 May;6(5):452-61. doi: 10.1016/j.jcin.2012.11.014. Epub 2013 Apr 17.
Coronary obstruction following transcatheter aortic valve implantation: a systematic review.
Ribeiro HB1, Nombela-Franco L, Urena M, Mok M, Pasian S, Doyle D, DeLarochellière R, Côté M, Laflamme L, DeLarochellière H, Allende R, Dumont E,Rodés-Cabau J.
OBJECTIVES:
This study sought to evaluate, through a systematic review of the published data, the main baseline characteristics, management, and clinical outcomes of patients suffering coronary obstruction as a complication of transcatheter aortic valve implantation (TAVI).
BACKGROUND:
Very few data exist on coronary obstruction after TAVI.
METHODS:
Studies published between 2002 and 2012, with regard to coronary obstruction as a complication of TAVI, were identified with a systematic electronic search. Only the studies reporting data on the main baseline and procedural characteristics, management of the complication, and clinical outcomes were analyzed.
RESULTS:
A total of 18 publications describing 24 patients were identified. Most (83%) patients were women, with a mean age of 83 ± 7 years and a mean logistic European System for Cardiac Operative Risk Evaluation score of 25.1 ± 12.0%. Mean left coronary artery (LCA) ostium height and aortic root width were 10.3 ± 1.6 mm and 27.8 ± 2.8 mm, respectively. Most patients (88%) had received a balloon-expandable valve, and coronary obstruction occurred more frequently in the LCA (88%). Percutaneous coronary intervention was attempted in 23 cases (95.8%) and was successful in all but 2 patients (91.3%). At 30-day follow-up, there were no cases of stent thrombosis or repeat revascularization, and the mortality rate was 8.3%.
CONCLUSIONS:
Reported cases of coronary obstruction after TAVI occurred more frequently in women, in patients receiving a balloon-expandable valve, and the LCA was the most commonly involved artery. Percutaneous coronary intervention was a feasible and successful treatment in most cases. Continuous efforts should be made to identify the factors associated with this life-threatening complication to implement the appropriate measures for its prevention.
10. Other complications of TAVR: - Heart block with need for pacemaker placement. Increased risk in people with RBBB. PARTNER trial showed similar risk of heart block comparing surgery and Sapien valve, higher risk with CoreValve.
- Paravalve regurg-- higher risk in people with heavily calcified annulus, prosthesis too small, not opening the balloon enough during the valvuloplasty (but if you open it too much you risk valve rupture! Devastating complication). Paravalve regurg assoc with worse outcomes. PARTNER trial data- mild paravalve regurg in ~40%, moderate/severe in ~10% at 2 years. Regurg is assoc with increased mortality (HR >2), however its not controlled for degree of co-morbidity.
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