low flow aortic stenosis-latest explanations
DESCRIPTION
Low Flow Low Gradient AS, a very important concept among echocardiologists and PhysiciansTRANSCRIPT
![Page 1: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/1.jpg)
![Page 2: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/2.jpg)
LOW FLOW AS
DR. DEEP CHANDH RAJA S
![Page 3: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/3.jpg)
• Aortic stenosis is the 3 rd most common CV disease after HTN and CAD (in western world)
• Prevalence is 2-7% over the age of 65 years• Evaluation of aortic stenosis is the most
challenging of all valvular heart diseases
Stewart BF, Siscovick D, Lind BK, et al. Clinical factors associated with calcific aortic valve disease. Cardiovascular Health Study. J Am Coll Cardiol 1997; 29:630–634.
![Page 4: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/4.jpg)
2 MAJOR GUIDELINES
• ACC 2006• ESC 2012A FEW IMPORTANT NEW CONCLUSIONS IN ESC
2012 BASED ON EVOLVING NEW CONCEPTS AFTER 2007 (MISSING IN ACC 2006)
![Page 5: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/5.jpg)
ACC/AHA GUIDELINES PUBLISHED IN JACC, 2006
![Page 6: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/6.jpg)
GRADIENT = FLOW DEPENDENT VARIABLEGradient calculation-Small reduction in flow can cause great reductions in gradient
![Page 7: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/7.jpg)
AVA calculation is a standard and must be incorporated into a comprehensive evaluation of AS severity
AVA=FLOW INDEPENDENT VARIABLE
![Page 8: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/8.jpg)
![Page 9: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/9.jpg)
MISMATCH BETWEEN GRADIENTS AND VALVE AREA
![Page 10: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/10.jpg)
1. INDEXING TO BSA
2. INACCURACY IN CALCULATION OF LVOT DIAMETER
3. WHO SAID AVA < 1.0 CORRESPONDS TO GRADIENTS > 40 ???
4. LOW FLOW STATE (DEFINED SVi <35 ml/mt2)
![Page 11: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/11.jpg)
• INDEXING TO BSA
Eg: AVA of 0.9 cm2, BSA=1.3, iAVA= 0.7 cm²/m²
AVA of 1.2 cm2, BSA=2.1, iAVA= 0.57 cm²/m²
![Page 12: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/12.jpg)
•INACCURACY IN CALCULATION OF LVOT DIAMETER
CSA= .785 X LVOT D 2
Eg: D=2.8, CSA= 6.15 D=2.2, CSA= 3.75
![Page 13: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/13.jpg)
• WHO SAID AVA < 1.0 CORRESPONDS TO GRADIENTS > 40 ???
Carabello demonstrated in 2427 patients, that“a mean gradient of 26 mmHg actually yields to an AVA of 1.0 cm², whereas a
mean gradient >40 is corresponding with a AVA of 0.8 cm2”
INCONSISTENCIES IN GUIDELINES- “FOR NOW, WE NEED TO ACCEPT AVA <1.0, AS THE REFERENCE CUT OFF TO DEFINE SEVERE AS”
![Page 14: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/14.jpg)
• INDEXING TO BSA
• INACCURACY IN CALCULATION OF LVOT DIAMETER
• WHO SAID AVA < 1.0 CORRESPONDS TO GRADIENTS > 40 ???
• LOW FLOW STATE (DEFINED AS SVi<35 ml/mt2)
![Page 15: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/15.jpg)
• H/O72 yr old ManHTN,
Dyslipidemia,CAD• C/ODOE & AOE
CLASS II
• AV GRADIENTS=43/28
• LVEF= 32 %• iAVA= 0.5 cm2
Case Scenario
![Page 16: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/16.jpg)
• H/O72 yr old ManHTN,
Dyslipidemia,CAD• C/ODOE & AOE
CLASS II
• AV GRADIENTS=43/28
• LVEF= 52 %• iAVA= 0.5 cm2
Case Scenario
![Page 17: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/17.jpg)
Causes of low flow state
• Till 2007 low flow due to LOW EF
• NOW low flow can also be secondary to Preserved EF “new entity” Paradoxical Low flow AS
![Page 18: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/18.jpg)
![Page 19: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/19.jpg)
Prevalence of low flow state
– LOW EF 5- 10 % of all patients of AVA < 1.0– PRESERVED EF 10-25 % of all patients of AVA < 1.0 IMPLICATION-“IF WE DON’T CALCULATE AVA, WE WILL MISS 15-35 %
OF CASES OF CRITICAL AS, MORE IMPORTANTLY WE WILL DEPRIVE THESE PATIENTS OF THE POTENTIAL BENEFIT OF AVR ON THEIR SYMPTOMS/SURVIVAL”
Pibarot P, Dumesnil J. Low-Flow, Low-Gradient Aortic Stenosis With Normal and Depressed Left Ventricular Ejection Fraction. J Am Coll Cardiol 2012;60:1845–53
![Page 20: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/20.jpg)
LOW FLOW STATE
• LOW EF
• PRESERVED EF
![Page 21: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/21.jpg)
• PATHOPHYSIOLOGY
• DIAGNOSIS
• TREATMENT OPTIONS
• PROGNOSIS
![Page 22: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/22.jpg)
LOW FLOW, LOW EF, SEVERE AS
![Page 23: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/23.jpg)
Case Scenario• H/O72 yr old ManHTN,
Dyslipidemia,CAD• C/ODOE & AOE
CLASS II
• AV GRADIENTS=44/26• iAVA= 0.5 cm2
• LVEF= 30 %
LOW FLOW, LOW GRADIENT, SEVERE AS WITH LOW EF
![Page 24: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/24.jpg)
Prevalence of low flow state
LOW EF 5- 10 % of all patients of AVA < 1.0PRESERVED EF 10-25 % of all patients of AVA < 1.0
Pibarot P, Dumesnil J. Low-Flow, Low-Gradient Aortic Stenosis With Normal and Depressed Left Ventricular Ejection Fraction. J Am Coll Cardiol 2012;60:1845–53
![Page 25: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/25.jpg)
PATHOPHYSIOLOGY
• LOW FLOW secondary to LOW EF• LOW EF is due to myocardial
dysfunction
“whether this myocardial dysfunction is-secondary to AS -secondary to other causes, or -primary myocardial disease, needs to be
evaluated”
![Page 26: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/26.jpg)
MYOCARDIAL DYSFUNCTION SECONDARY TO CAUSES OTHER THAN AS
-DILATED CARDIOMYOPATHIES (1O MYOCARDIAL DYFUNCTION)
-ISCHEMIC HEART DISEASE
-HTN HEART DISEASE (AFTER LOAD MISMATCH)
In all these patients, AVA was misjudged as <1.0 due to incomplete opening of AV due to low EF and labelled as “PSEUDO SEVERE AS”
![Page 27: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/27.jpg)
MYOCARDIAL DYSFUNCTION SECONDARY TO AS
• “ True severe AS”• Removal of the only afterload-AS can lead to
dramatic improvements in patients’ symtoms/survival compared to medical therapy alone
![Page 28: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/28.jpg)
DIAGNOSIS
![Page 29: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/29.jpg)
DIAGNOSIS
• FIRST SUSPICION GRADIENT-AVA MISMATCH during routine echo
• GRADIENT < 40 mmhg, AVA <1.0, EF <40 %
• Dobutamine stress echo (exercise stress echo)Class IIA recommendation
![Page 30: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/30.jpg)
Dobutamine stress echo
• Low dose protocol upto 20 µg/kg/mt• We look for three things:-Flow reserve -Change in EOA-Change in Gradient
![Page 31: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/31.jpg)
30-40%
20-30%
![Page 32: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/32.jpg)
Projected EOA
TOPAS (True or Pseudo Severe AS) STUDY
![Page 33: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/33.jpg)
CT AV CALCIUM SCORING
Cueff et al. suggested that a score >1,650 Agatston units provides good accuracy (93 % sensitive, 75 % specific) to distinguish true severe from pseudosevere AS
![Page 34: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/34.jpg)
Treatment Decisions
![Page 35: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/35.jpg)
• SYMPTOM STATUS
• VALVULAR SEVERITY
“ANY SYMPTOMATIC SEVERE AS, IRRESPECTIVE OF EF AND FLOW RESERVE, HAS TO BE INTERVENED (class I)”
WITHOUT AVR, 1 YR. MORTALITY IS 30-50% (Turina et al EhJ 1987)
![Page 36: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/36.jpg)
Severe ‘Asymptomatic’ AS WITH LOW EF
• WITH NORMAL EF-management is challenging, an abnormal response to exercise stress testing and elevated BNP may identify a higher-risk group that might benefit from closer followup and earlier surgery
Recommendation:AVR for patients who have no symptoms and whose left ventricular ejection fraction is less than 50% (class I indication, level of evidence C)
![Page 37: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/37.jpg)
• EURO SCORE, STS SCORE• PERIOP RISK- FLOW RESERVE (+)=5-8%,FLOW RESERVE (-)=30%*
![Page 38: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/38.jpg)
Role of TAVI• Operative risk for open heart surgery is generally very
high in absence of flow reserve• TAVI - valuable alternative in these patients• Recent studies reported a greater and more rapid
improvement of LVEF in patients treated by TAVR than those treated by surgical AVR *
• RATIONALE related to a lesser incidence of patient–prosthesis mismatch.
• In contrast, TAVR associated with a higher incidence of paravalvular regurgitation, stroke, vascular complications which may eventually have a negative impact on outcomes
• PARTNER A & B and STACCATO TRIALS*Clavel et al. Circulation 2010;122:1928 –36
![Page 39: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/39.jpg)
• Normal flow reserve: Medical followup every 6 months vs AVR (ESC class IIa)–based on the clinician’s
judgement• Low flow reserve:1.IHD-OMT ± revascularisation 2.HTN- to be treated3.Optimal heart failure management strategy4.AVR (ESC class IIb)
![Page 40: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/40.jpg)
Concerns after AVR• Patient-Prosthesis MISMATCH• LOW EF patients are known to be more
vulnerable than patients with normal LVEF to the excess in LV load
• Can cause acute decompensation of LV or inadequate improvement of LV functions after AVR
• Paravalvular leak, Stroke in TAVI (Kodali et al.NEJM 2012)
![Page 41: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/41.jpg)
PROGNOSIS
![Page 42: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/42.jpg)
Prognosis • Concomitant CAD (46-79 %)• LOW EF SEVERE AS compared to Normal EF severe AS
have higher periop mortality rates (6-33%), depending on presence of myocardial contractile reserve (5-8%) or not (22-33%)
• BUT, irrespective of degree of myocardial dysfunction or contractile reserve, the patients benefit more from AVR than medical treatment only
“Severe LV dysfunction IS NOT A CI FOR AVR, albeit the high risk of surgery in these patients”
![Page 43: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/43.jpg)
Group I= Flow reserve +Group II= Flow reserve -
![Page 44: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/44.jpg)
Predictors of late mortality
• Preop. Contractile reserve• EuroSCORE, STS score, • Atrial fibrillation, • Multivessel CAD, • Low pre-operative gradient, • High plasma levels of BNP, and • Patient–prosthesis mismatch
![Page 45: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/45.jpg)
• Low Flow due to low EF
• DSE to differentiate True from Pseudo Severe AS
• EOA (proj) & CT AV Ca Score
• AVR irrespective of EF and Flow reserve
![Page 46: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/46.jpg)
![Page 47: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/47.jpg)
LOW FLOW NORMAL EF SEVERE AS“PARADOXICAL”
![Page 48: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/48.jpg)
Case Scenario• H/O72 yr old ManDyslipidemia,CAD• C/ODOE & AOE
CLASS II
• AV GRADIENTS=53/32
• LVEF= 62 %• iAVA= 0.5 cm2
• Gr 2 DD e/e’=12
LOW FLOW, LOW GRADIENT, SEVERE AS WITH NORMAL EF
![Page 49: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/49.jpg)
Prevalence of low flow state
LOW EF 5- 10 % of all patients of AVA < 1.0PRESERVED EF 10-25 % of all patients of AVA < 1.0
Hachicha Z, Dumesnil JG, Bogaty P, Pibarot P. Paradoxical low flow, low gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival. Circulation 2007;115:2856–64
![Page 50: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/50.jpg)
New Entity
• First reported in 2007 by Hacicha et al. in 512 pts. (CIRCULATION)
• ECHO PROFILE:-Mean gradient < 40 mmhg,-AVA < 1.0 cm2,-Flow <35 ml/mt2,-EF≥40 %
![Page 51: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/51.jpg)
PATHOPHYSIOLOGY AND CHARACTERISTICS OF LOW FLOW
NORMAL EF SEVERE AS
![Page 52: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/52.jpg)
• Myocardial fibrosis• Restrictive physiology• Small LV cavity• Resembles heart failure
with preserved EF (Diastolic Heart failure)
• Pseudo-normalization of blood pressure
• Impaired LV function yet normal EF
(around 50-60%)
![Page 53: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/53.jpg)
DIAGNOSIS
![Page 54: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/54.jpg)
“Normal LVEF Does Not Mean Normal Myocardial Function”
• LVEF is a late and insensitive marker for study of LV functions
• Not too far that LVEF will be replaced by other better markers of LV function
![Page 55: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/55.jpg)
ALTERNATIVES TO ‘EF’
• Valvulo-Arterial Impedance (Zva) • MPI (Tei Index)• Mitral annular displacement (By TDI)• Global LV Strain• CT AV Calcium Scoring• BNP levels
>5.5
>0.42
< 12 mm
< 10%
>1650 AU
>550 pg/ml
![Page 56: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/56.jpg)
Valvulo-Arterial impedance (Zva)• A measurement of “afterload”• Just quantifies the total load, that helps in
prognostication• Values > 3.5 Zva(mmHg·mL-1·m2) call for
reduction in load- (both valvular and vascular)• Does not differentiate between the type of
load –valvular vs vascular• Does not differentiate moderate vs severe AS
(SBP + Mean AV Gradient) / i SV
![Page 57: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/57.jpg)
TREATMENT DECISIONS
![Page 58: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/58.jpg)
• 2012 ESC guidelines class IIa indication for AVR
• “This subgroup of patients seems to be at a more advanced stage and has a poorer prognosis if treated medically rather than surgically”
• It remains to be determined if TAVI could not be a better alternative in these patients
Tarantini G, Covolo E, Razzolini R, et al.The Annals of Thoracic Surgery, Volume 91(6)
LOW FLOW, NORMAL EF, SEVERE AS
![Page 59: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/59.jpg)
PROGNOSIS
![Page 60: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/60.jpg)
LOW FLOW, N.EF, SEVERE AS
• Worse than moderate AS (albeit contradictory reports)
• Worse than severe AS with high gradient grouplower overall 3-year survival (76% versus 86%; P<0.006 in 512 patients By Hacicha et al.)• Two-fold increase in mortality and an almost
50% lower referral rate for AVR in the low-gradient AS compared to the high gradient group (Barasch et al)
![Page 61: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/61.jpg)
FUTURE TERMINOLOGY
• SEVERE AS WITHOUT MYOCARDIAL DYSFUNCTION
• SEVERE AS WITH MYOCARDIAL DYSFUNCTION
-SEVERE AV STENOSIS BASED ON AVA -IRRESPECTIVE OF FLOW, GRADIENTS, EF
![Page 62: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/62.jpg)
SUMMARY
![Page 63: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/63.jpg)
• ACCURATE AVA CALCULATION BY CONTINUITY EQUATION MUST BE A STANDARD IN EVALUATION OF A.S BY ECHO
• ELSE WE ARE GOING TO MISS 30 % CASES OF SEVERE AS
• LOW FLOW AS COULD BE DUE TO BOTH NORMAL AND REDUCED EF
• INSTITUTION PROTOCOLS TO BE DESIGNED FOR EVALUATION AND TREATMENT OF LOW FLOW STATES
![Page 64: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/64.jpg)
• Low Flow due to low EF
• DSE to differentiate True from Pseudo Severe AS
• EOA (proj) & CT AV Ca Score
• AVR irrespective of EF and Flow reserve
![Page 65: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/65.jpg)
• Low Flow due to intrinsic myocardial dysfunction
• Better picked up by novel methods of LV function like MAD, Tei index, Strain apart from Zva, BNP levels
• AVR better than medical management
![Page 66: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/66.jpg)
SEVERE AS (indexed AVA < 0.6 cm2)
ASYMPTOMATIC NORMAL EF NORMAL FLOW EXERCISE TESTING(IIa) &FOLLOW UP
ASYMPTOMATIC LOW EF LOW FLOW AVR (I)
SYMPTOMATIC NORMAL EF NORMAL FLOW AVR (I)
SYMPTOMATIC LOW EF(EVEN IF FLOW RESERVE IS LOW)
LOW FLOW AVR (I)
SYMPTOMATIC NORMAL EF LOW FLOW AVR (IIa)
PSEUDO-SEVERE AS (AVA <1.0 cm2 in ECHO, AVA >1.2 cm2 in DSE)
SYMPTOMATIC LOW EF NORMAL FLOW RESERVE AVR (IIa)
SYMPTOMATIC LOW EF LOW FLOW RESERVE AVR (IIb)
MODERATE AS (AVA 1-1.5 cm2)
ASYMPTOMATIC NORMAL EF FOLLOW UP
SYMPTOMATIC NORMAL EF FOLLOW UP, AVR (IIb)
![Page 67: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/67.jpg)
Simplified Statement
“Irrespective of AV Gradients and LVEF, symptomatic patients with iAVA < 0.6 cm2, and CT AV calcium score > 1650 AU, should be referred for AVR”
![Page 68: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/68.jpg)
GREY AREAS
• AS WITH AR• AS WITH MITRAL VALVE DISEASE• RHEUMATIC AS
“Inadequate, less reliable literature”
![Page 69: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/69.jpg)
“TAVI may eventually prove to be an attractive alternative to surgical AVR in both types of LF-LG severe AS, but this remains to be confirmed by future randomized studies”
![Page 70: Low flow Aortic Stenosis-latest explanations](https://reader034.vdocuments.us/reader034/viewer/2022042700/5586331bd8b42a4c578b50de/html5/thumbnails/70.jpg)