Early and short term outcomes of an indian bioprosthetic valve at mitral and aortic positions

R Karthik Raman

Consultant – Cardiac Surgery, Kauvery Heart City, Trichy, Tamil Nadu

Aims and Objectives

Short term outcomes of Dafodil valve in mitral and aortic positions

Outcome variables:

In hospital mortality
Freedom from re operation (all cause)
Freedom from Non Structural Valve Deterioration (NSVD)
Freedom from Structural Valve Deterioration (SVD)
Freedom from heart failure
Freedom from Infective Endocarditis (IE)
All at the end of 2 years

Materials and Methods

Study Design: Single centre retrospective multi variate analytical study

Study Duration: January 2022 till April 2025.

Valves included: Dafodil bioprosthetic valve in both mitral and aortic positions

Dafodil valve

Bovine pericardial tissue
Elgiloy stent material
Position-specific design for both mitral and aortic locations
Unique Delivery System for Mitral Position – Active flex technology (synching equivalent)
Triple-composite design – three independent pericardial leaflets
Commissural markers on the sewing ring

Sample size: 114 patients

Follow up period (97.8% complete): 3120 patients’ months global loss to follow up- 3.2%

Inclusion criteria

All adult patients > 18 years who underwent Mitral Valve Replacement (MVR) and Aortic Valve Replacement (AVR) using Daffodil valve.
Concomitant procedures.
Redo surgeries.
Double valve replacements (DVR)-AVR and MVR.

Exclusion criteria

All mechanical valves.
Bioprosthetic valves other than the valve in study.

Surgical technique

Cardio pulmonary bypass with Aorto bicaval cannulation for MVR and aorto double stage single venous cannulation for AVR. Moderate hypothermia (28ºC) with antegrade delNido Aortic root/ostial cardioplegia.
Through a left atriotomy (waterston’s groove) for MVR and transverse aortotomy for AVR.
new valve implanted using 2-0 poleyester interrupted sutures pledgets facing la side for MVR and LV side for AVR.

Anticoagulation strategy

Acitrom to maintain an International Normalised Ratio (INR) of 2.5 to 3 for MVR, 2-2.5 for AVR and 2.5 – 3 for DVR
To check INR once weekly in first month, fortnightly in second and third month.
Anticoagulation till three months unless there is another indication to continue it.

Data analysis

S no	Pre op criteria	MVR	AVR	DVR
1	No of patients (n)	56	52	6
2	Age years
2	Range	53-72	51-75	55-70
3	Gender
	Male(n)	46 (82%)	34 (65%)	4 (67%)
	Female(n)	10(18%)	18 (35%)	2( 33%)
4	Aetiology (n)
	Rheumatic	46	15	6
	Ischemic	6	0	0
	Degenerative	4	7	0
	Bicuspid	0	30
5	Lesion (n)
	Stenosis	25	18
	Regurgitant	10	19
	Mixed	21	15	6
6	Pre op NYHA class (n)
	I	-	-
	II	50	42
	III	6	10
	IV
7	Rhythm (n)
	Sinus	48	49	6
	Atrial fibrillation	8	3
	Other than the above two
8	Pre op LVEF (n)
	>50%	46	44	4
	35-50%	9	6	2
	20-35%	1	2
9	EURO Score - II	3.4 ± 1.2	2.6 ± 2.1	4.2 ± 0.5
10	Peak gdt - mmhg (for pure stenotic lesion)	18 ± 4	127 ± 20
11	Mean gdt – mmhg (for pure stenotic lesion)	11 ± 2	67 ± 4

Intra op variables

S no	Intra op variable	MVR	AVR	DVR
1	Valve size (n)	25 mm-8	19 mm- 40	19mm- 1
		27 mm-46	21 mm- 11	21mm- 1
		29 mm-1	23 mm- 1	25mm-2
		31 mm-1
2	Associated procedures (n)
	CABG	5	8
	Tricuspid valve repair	2	-	2
	Others	1	-
3	Cardio Pulmonary Bypass time (min)	87±67	110±28	154±14
4	Aortic Cross Clamp time (min)	67±12	87±14	132±14

Follow up data

S No	Variable	MVR	AVR	DVR
1	In-hospital Mortality (up to 30 days)	2	1	–
2	Follow-up Mortality	–	1	–
3	Peak gdt (mmhg) (Comparison from pre op gdt)	8±2 (18±4 P = 0.03)	25±10 (127±20 P = 0.01)	–
4	Mean GDT (mmHg) – Post-op	4±2 (11±2 P = 0.04)	17±5 (67±4 P = 0.03)	–

Causes of Death

MVR group

1 Patient – sepsis operated for infective endocarditis.
1 patient – stroke

AVR group

1 Patient – para valvular leak
1 Patient – renal dysfunction

Linearized incidence rates during follow up

S no	Event (%/Patient year)	MVR	AVR	DVR
1	In hospital mortality	3.5%	1.1%	-
2	SVD	-	-	-
3	NSVD	-	1.2%	-
4	IE	-	-	-
5	Re operation (all cause)	-	-	-
6	Thrombo embolic events	1.8%	0.3%	-
7	Bleeding	1.5%	1.0%	-
8	Heart failure (not valve related)	1.3%	1.1%	-

Freedom from event rates

S no	Event (95% CI)	MVR	AVR	DVR
1	Actuarial survival rate	97±0.1% (9.3-11.1)	99±2.3%(9.4-11.2)	100%
2	SVD	100%	100%	100%
3	NSVD	100%	97±1.1% (8.9-11.1)	100%
4	IE	100%	100%	100%
5	Re operation (all cause)	100%	100%	100%
6	Thrombo embolic event	98.2±0.08% (9.5-9.8)	99.2±0.04% (9.7-10.03)	100%
7	Bleeding event	96.5±0.02% (9.5-9.8)	97.5±0.08% (9.7-10.03)	100%
8	Heart failure (not valve related)	99±0.08% (9.7-10.2)	98.2±0.07% (9.4-10.2)	100%

Actuarial survival curve

Green line – MVR

Blue line – AVR

Freedom from NSVD

Blue line- MVR

Green line – AVR

Explant due to SVD by age group- competing risk regression (actual) estimates

For example, a 60-year-old patient has a 20% probability of needing a reoperation due to SVD after 15.7 years; the probability increases to 50% after 18.4 years.

Conclusion

Indian bioprosthetic valve performs well at both aortic and mitral positions.
Short term outcomes – no incidence of SVD.
Needs long term follow up for further confirmation.
More numbers need to be recruited.

Conflict of interest: None

Funding: None

Kauverian Bookshelf

Applied Medical Statistics

Early and short term outcomes of an indian bioprosthetic valve at mitral and aortic positions