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Knowledge Regarding Oral Anticoagulant Therapy among Patient with Mechanical Heart Valve Replacement: A Cross-Sectional Study in

May 2023

Authors:

Abasyn University

Objectives: To determine the knowledge of mechanical heart valve replacement patients regarding oral anticoagulants. Materials and Methods: A cross-sectional study on patients with mechanical valve prostheses was conducted at Lady Reading Hospital Peshawar, Khyber Pakhtunkhwa, Pakistan. The duration of the study was 6 months. Overall, 345 participants were included in the study. Consecutive sampling technique has been used. Information was collected using adopted, validated questionnaire. Results: Overall, 345 patients with mechanical valve prostheses were included in the study with mean age of the participants were 37.91 years. The age of the participants were ranging from 19 to 62 years. Male patients (59%) exceeded female patients (41%). Only 10% study patients received education regarding oral anticoagulant therapy. Majority (78.3%) patients had inadequate overall knowledge score regarding oral anticoagulants (Warfarin) while 16.5% had moderate adequate knowledge and 5.2% had adequate knowledge score. Conclusion: The majority of studied patients had inadequate overall knowledge regarding oral anticoagulant (Warfarin). Patient's education in health care setups is very low. Area of improvement in patient's education has been identified. There is need of strategies to improve the patient's knowledge regarding oral anticoagulant to minimize the risk of therapy.

Demographic Profile of the study population, (n=345).

…

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International Journal of Medical Science and Advanced Clinical Research (IJMACR)

Available Online at: www.ijmacr.com

Volume – 2, Issue – 6, November - December - 2019, Page No. : 173 – 180

Corresponding Author: Roheeda Amanullah Khan, Volume - 2 Issue - 6, Page No. 173 – 180

Page 173

ISSN: 2581 – 3633

PubMed - National Library of Medicine - ID: 101745081

Knowledge Regarding Oral Anticoagulant Therapy among Patient with Mechanical Heart Valve Replacement: A

Cross-Sectional Study in Peshawar, Khyber Pakhtunkhwa.

1Roheeda Amanullah Khan.RN.RM.BScN.MScN., Institute of Nursing sciences, KMU.

2Prof Dr Riaz Anwar Khan, HOD, Cardiac Surgary, LRH, Peshawar.

3Dr Dildar Khan, BSN.PhD.MHPE.

4Sardar Ali, BSN.MSN.MHPE.INS KMU.

5Rashida Bibi, R.RM.PRN.BScN.MSc N.

6Nusrat Noreen, R.RM.PRN.BScN.MSc N.

Corresponding Author: Roheeda Amanullah Khan, RN.RM.BScN. MScN., Institute of Nursing sciences, KMU.

Type of Publication: Original Research Paper

Conflicts of Interest: Nil

Abstract

Objectives: To determine the knowledge of mechanical

heart valve replacement patients regarding oral

anticoagulants.

Materials and Methods: A cross-sectional study on

patients with mechanical valve prostheses was conducted

at Lady Reading Hospital Peshawar, Khyber

Pakhtunkhwa, Pakistan. The duration of the study was 6

months. Overall, 345 participants were included in the

study. Consecutive sampling technique has been used.

Information was collected using adopted, validated

questionnaire.

Results: Overall, 345 patients with mechanical valve

prostheses were included in the study with mean age of

the participants were 37.91 years. The age of the

participants were ranging from 19 to 62 years. Male

patients (59%) exceeded female patients (41%). Only 10%

study patients received education regarding oral

anticoagulant therapy. Majority (78.3%) patients had

inadequate overall knowledge score regarding oral

anticoagulants (Warfarin) while 16.5% had moderate

adequate knowledge and 5.2% had adequate knowledge

score.

Conclusion: The majority of studied patients had

inadequate overall knowledge regarding oral anticoagulant

(Warfarin). Patient’s education in health care setups is

very low. Area of improvement in patient’s education has

been identified. There is need of strategies to improve the

patient’s knowledge regarding oral anticoagulant to

minimize the risk of therapy.

Keywords:

Oral Anticoagulant, Warfarin, Knowledge, Mechanical

heart valve replacement.

Introduction

Cardiovascular diseases (CVD) are the main cause of

death. Around 30% to 40% of deaths globally are due to

cardiovascular diseases. CVD cause more than 19% of

deaths in the developing countries which is the highest

number of death as compared to other diseases(1). More

than 65 million deaths worldwide are caused by

cardiovascular diseases. 80% of all cardiovascular

diseases occurred in developing countries(2).Nearly

accounts for nearly 610000 deaths per year which is one

Roheeda Amanullah Khan, et al. International Journal of Medical Sciences and Advanced Clinical Research (IJMACR)

Page174

out of three deaths in United States (US) (3). Even the rate

of mortality reduced from 1979 to 2015(4). More than

26000 Trans-catheter aortic valve replacements have been

performed from 2011 – 2014 at 348 centers in 48 states of

America (5).

One of the major categories of cardiovascular diseases is

Valvular Heart Disease (VHD). Valvular heart disease is a

significant problem in the developing countries in which

the primary sufferers from Valvular heart diseases are

children and adults. Valvular heart diseases prevalence is

more common in men than women (6). Moderate to severe

Valvular diseases cases are notable more common in

geriatric population. With aging, the valves of the heart

deteriorate its function which lead to sever heart problems

even death (7).

To maintain the function of the heart of Valvular heart

diseased patient and to reduce premature mortality from

cardiovascular disease, valve replacement is necessary.

Heart valve replacement is the most effective and

appropriate management for Valvular Heart Disorders (8).

The most common and effective procedure of cardiac

valve replacement is the Prosthetic valve replacement,

which is usually done when the cardiac valve is unable to

perform its function. On one hand the procedure is

effective and appropriate management of VHD, on the

other hand this procedure has several complication which

can even lead to death (9).. Bleeding, valve dysfunction of

the replaced valve, heart rhythm problems, stroke

infection and blood clots formation are some of the

complications of Valvular heart replacement procedure.

Among all the complications the most important one is

thrombotic event. Thrombotic event can cause stroke

when it block the supply of the blood to the brain can lead

to death (10) .

There are certain ways used to reduce the

complications of MHVR in which the most important one

is the use of oral anticoagulant therapy (warfarin). Oral

anticoagulant (OAC) are postoperative therapy, used to

overcome the occurrence of thrombosis(11).Anticoagulant

treatment is standard therapy in post heart valve replaced

patients. OAT prevents formation of thrombosis and also

prevents the occurrence of stroke. Among oral

anticoagulants warfarin is the best medicine used for heart

valve replaced patients (12).

OAT increases the life expectancy of post-operative heart

valve replacement patients. These medications can be used

for life long with very low side effects if the patients

observe PT/INR in therapeutic range. PT/INR above the

normal range may lead to severe bleeding and thrombosis

(13).

Only patients can monitor PT/INR themselves for any

complication of oral anticoagulant therapy (OAT)

Warfarin. Meanwhile it is very important for patients to

know about OAT for optimal health. Patients Nurses

should educate the patients about OAT. Low patient’s

knowledge may lead to sever problems. One side warfarin

prevent clots formation while another side it causes

thrombosis(14).

No study was found in Pakistan on “Knowledge regarding

oral anticoagulant therapy among patient with mechanical

heart valve replacement” (MHVR). This paper will

discuss methods used to systematically search, retrieve

and appraise evidence on Knowledge regarding oral

anticoagulant therapy among patient with (MHVR).

Studies included in the review were presented

comprehensive evidence on Knowledge regarding OAT

among patient with mechanical heart valve replacement.

Subjects and Methods

A descriptive cross-sectional study on patients with

mechanical valve prostheses was conducted at Lady

Reading Hospital Peshawar, Khyber Pakhtunkhwa,

Pakistan. The duration of the study was 6 months, starting

from February 2019 to August 2019.

Roheeda Amanullah Khan, et al. International Journal of Medical Sciences and Advanced Clinical Research (IJMACR)

Page175

With 95% confidence level, margin of error of 5% and

population proportion of 66% the sample size for the

study was 345 subjects. Consecutive sampling technique

has been used. Study was conducted after approval of

ASRB and ethical review board of KMU.

Data was collected using adopted Oral Anticoagulant

Knowledge test (OAK) questionnaire from post-operative

mechanical heart valve replacement patients. The

questionnaire was standard and validated (Cronbach’s

alpha = 0.767). The questionnaire was translated to Urdu

and the content validity index calculated was 0.93 with

five expert’s opinion of Government College and

cardiovascular surgeons of Lady Reading Hospital

Peshawar.

Knowledge of participants regarding oral anticoagulant

therapy was recorded as inadequate, moderate adequate

and adequate knowledge. Data was analyzed using SPSS

24.

Results

A total of 345 post-operative mechanical heart valve

replacement patients who were on warfarin therapy were

included in the study. The age of the participants ranged

from 19 to 62 years. Mean age of the participants was

37.91 years. Nearly half (46%) of the study participants

were in range of 31-40 years, followed by 40-50% which

is 27%. More than half (59%) study participants were

male while 41% participants were female. The huge

numbers (n=299) of post-operative prosthetic valve

patients were married. More than half (58%) participants

were using warfarin therapy for less than three years.

Mitral valve was the most affected heart valve of the study

participants reported by 62% participants. Similarly,

Aortic heart valve replacement was reported by 21%

participants. Both Mitral and Aortic valve were replaced

in 15% of study population. Majority (51%) study

participants were having primary level of education; only

4% participants were having master level of education

(Table 1).

Table 1: Demographic Profile of the study population, (n=345).

Frequency

Percent

Valid Percent

Cumulative Percent

Gender

Male

205

59.4

Female

140

40.6

100.0

Age (Years)

< than 20 years

1.2

21 -30 years

20.3

21.4

31-40 years

158

45.8

67.2

40-50 years

27.0

94.2

> than 50 years

5.8

100.0

Social Status

Roheeda Amanullah Khan, et al. International Journal of Medical Sciences and Advanced Clinical Research (IJMACR)

Page176

Married

299

86.7

Unmarried

13.0

99.7

Divorced

0.3

100.0

Duration of Warfarin Therapy (Years)

< than 3 years

202

58.6

4-7 years

17.4

75.9

8-10 years

17.1

93.0

> than 10 years

7.0

100.0

Prosthesis Position

Mitral

215

62.3

Aortic

21.7

84.1

Mitral and Aortic

15.9

100.0

Education

Primary

176

51.0

Matric

105

30.4

81.4

FA/FSC

14.2

95.7

Master

4.3

100.0

Table 2: Knowledge on oral anticoagulation therapy among valve replacement patients (N=345).

Level of Knowledge

Number

Percentage

Inadequate Knowledge (< than 50%)

270

78.3%

Adequate Knowledge (50 – 75%)

16.5%

Adequate Moderately Knowledge (> than 75%)

5.2%

Majority (78.3%) mechanical heart valve replacement

patients had inadequate knowledge, 16.5% participants

have adequate knowledge and only 5.2% respondents have

moderately adequate knowledge regarding oral

anticoagulant therapy (Table 2).

Roheeda Amanullah Khan, et al. International Journal of Medical Sciences and Advanced Clinical Research (IJMACR)

Page177

There was no significant association between the socio-

demographic variables and level of knowledge of

participants regarding oral anticoagulant therapy.

Discussion

Many studies have been conducted in different countries

to evaluate the knowledge of post-operative mechanical

valve replaced patients regarding oral anticoagulants

therapy (OAT) but no study has been conducted in

Pakistan regarding this issue.

The main purpose of the study was to determine the

knowledge regarding OAT (warfarin) therapy among

patients with mechanical heart valve replacement

(MHVR). Overall, 20 questions regarding the knowledge

were included in the study. The present study discovered

that majority of the study participants 78.3% had

inadequate overall knowledge score. However, the results

of the other studies evidenced moderate knowledge level

of majority (66.7%) participants with mechanical valve

replaced regarding OAT (15). Similarly, another study also

reported (61.8%) moderate knowledge in patients with

MHVR regarding OAT (16).

In addition, the results of the current study showed

majority (196) of patients responded missing one dose of

warfarin can alter the effectiveness of OAT. Literature

supports, that missing one dose of warfarin may alter the

effectiveness of OAT. It is necessary for patients to take

tablet warfarin on regular bases because missing dose can

alter the normal range of PT/INR (17). One other study also

estimated, if patient misses a single dose of warfarin and

if they remember the dose on the same day, so, it is

permissible to take the missing dose on the same day, but

if they remember it on the next day so they should not take

the missing dose because it can overdose the patient .The

patient should consult the physician regarding the missing

dose(16).(17).

The current study revealed that 70% participants reported

that they identify warfarin tablets by color. Literature also

supports that the best way to distinguish between different

strengths of warfarin is color distribution(18).

Furthermore, recent study showed (58%) of the MHV

patients reported that eating green leafy vegetables with

warfarin therapy increase the risk of thrombosis. 13%

participants respond that eating green leafy vegetables

reduce the effectiveness of warfarin. Similarly, the current

findings indicate that majority (55%) of respondent

reported that vitamin A interacts with warfarin and only

18% participants answered the correctly that vitamin K

interacts with warfarin. According to literature vitamin K

is the most important vitamin which interacts with

warfarin. It is recommended for the MHVR patients to

avoid eating green leafy vegetables to maintain INR in

normal range(19). Similarly, the findings were reported by

the study majority of the patients had low knowledge

about the influence of diet on OAT(20).

The current study showed very few patients (15%)

answered correctly about the situation in which they

should contact the primary physician, while other study

showed 66%patients answered correctly regarding contact

with primary physician while on OAT (21).

In the existing study more than half (58%) of the patients

with MHV gave correct answer about PT/INR test. The

patients responded that the PT/INR is a blood test used to

monitor warfarin therapy. In the same perspective, studies

reported majority of the patients responded that PT/INR is

a test for monitoring the OAT (22). In the same way,

literature also supports that PT/INR is a test for the

patients used OAT. PT/INR monitors the level of warfarin

and indicate the dose adjustment accordingly(23).

Majority (84%) of the participants from the recent study

reported that warfarin may be used to treat patients that

already have a blood clot, while 39% reported that

PT/INR is a blood test that is rarely done while on

warfarin. Similarly, patients with MHVR from other

Roheeda Amanullah Khan, et al. International Journal of Medical Sciences and Advanced Clinical Research (IJMACR)

Page178

studies also supports result of this study’s that (warfarin)

are used in patients who have already a blood clot (24).

In addition, results from this study highlighted that one

forth (25%) of patients with MHVR reported the correct

answer that PT/INR value below the normal range

increase the risk of clot, while 67% reported that it

increase the risk of bleeding of patients whose PT/INR is

below the normal range. Meanwhile others study showed,

majority of the patients know that PT/INR bellow the

normal range increase the risk of having a blood clot(25).

Only 10% of patients with MHVR from the current study

gave correct answer that medicines containing aspirin and

non-steroidal anti-inflammatory drugs (NSAID) may

increase risk of bleeding while on warfarin, likewise

majority (82%) participants reported that NSAID reduce

the effectiveness of the warfarin. In same context, results

from the other study showed majority of patients with

MHVR reported the correct answer that aspirin and

NSAID may increase the risk of bleeding in patients with

warfarin (26).

Less than quarter of the patients from the current study

with MHVR reported the correct answer regarding the

importance of monitoring of signs of bleeding while on

warfarin therapy. Majority (79%) responded with the

wrong answer reported that the patients on warfarin

therapy should only monitor sign of bleeding when their

PT/INR is above the normal range. In the same context,

results from other studies showed majority patients have

knowledge regarding the importance of monitoring sign of

bleeding while on warfarin therapy (27).

There are some contradictions between the results of the

current study as compared to other studies. Present study

reported only 10% patients with MHVR have received

adequate education about OAT which is very low

percentage; while studies reviewed above reported

majority of the participants received anticoagulant

education. Education regarding anticoagulant has a very

strong association with patient’s knowledge.

Conclusion

The majority of studied patients had overall inadequate

knowledge regarding OAT at the same time they had

inadequate knowledge about diet, therapeutic level and

preventive measures of complications. Since the patients

had less knowledge on effective dietary management and

drug compliance will increase the complications relates to

warfarin. Area of improvement in patient’s education has

been identified. There is need of strategies to improve the

patient’s knowledge regarding oral anticoagulant to

minimize the risk of therapy.

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ResearchGate has not been able to resolve any citations for this publication.

Assessment of patients’ warfarin knowledge and anticoagulation control at a joint physician- and pharmacist-managed clinic in China

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Dec 2018

Thus far, the target value for international normalized ratio (INR) has remained to be determined. The current study aimed to further explore the INR value of the anti-coagulation drug warfarin after cardiac valve replacement. The clinical data of 213 patients who underwent cardiac valve replacement at Linyi Central Hospital (Linyi, China) between January 2010 and May 2013 were retrospectively analyzed. The warfarin dosage, prothrombin time (PT) and INR were compared among patients with hemorrhage or embolism, and those with no complications. A total of 31 cases (14.6%) developed adverse reactions and complications during the medication period, including 21 cases with hemorrhage (9.9%, hemorrhage group) and 10 cases with embolism (4.7%, embolism group), while 182 patients did not (85.4%, normal group). The average dosage of warfarin was 2.0±0.6, 3.1±0.7 and 1.7±0.6 mg/day in the normal, hemorrhage and embolism groups, respectively. The dosage of warfarin, the PT and the INR in the hemorrhage group were all significantly greater than those in the normal group and the embolism group (all P<0.05). INR monitoring is recommended to ensure the safety of the anti-coagulant drug warfarin, but further study is still required to determine a reasonable target INR value.

Anticoagulation Management in Patients with Valve Replacement

Article

Jan 2018
J Assoc Phys India

background: Prosthetic valve implantation requires postoperative prophylactic anticoagulation to preclude thrombotic events. The aim of this review is to assess the role of anticoagulation therapy in the management of valve replacement patients. methodology: Literature from PubMed, Embase, Medline and Google Scholar were searched using the terms "valvular heart disease", "anticoagulant", "mechanical heart valve", "bioprosthesis", "bridging", "Vitamin K antagonist (VKA)", and "acenocoumarol". A committee comprising leading cardiothoracic surgeons from India was convened to review the literature and suggest key practice points. results: Prosthetic valve implantation requires postoperative prophylactic anticoagulation to preclude thrombotic events. A paramount risk of thromboembolic events is observed during the first three months after surgery for both mechanical and bioprosthetic devices. The VKA therapy with individualized target international normalized ratio (INR) is recommended in patients after prosthetic valve replacement. Therapies for the management of prosthetic valve complications should be based on the type of complications. Special care is mandated in distinguished individuals and those with various co-morbidities. conclusion: In patients with prosthetic valve replacement, anticoagulant therapy with VKA seems to be an effective option. The role for non-VKA oral anticoagulants in the setting of prosthetic valve replacement has yet to be established. Furthermore, whether the novel oral anticoagulants are safe and efficacious in patients after placement of a bioprosthetic valve remains unanswered.

Heart Disease and Stroke Statistics—2018 Update: A Report From the American Heart Association

Article

Jan 2018

Each year, the American Heart Association (AHA), in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together in a single document the most up-to-date statistics related to heart disease, stroke, and the cardiovascular risk factors listed in the AHA's My Life Check - Life's Simple 7 (Figure¹), which include core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure [BP], and glucose control) that contribute to cardiovascular health. The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions. Cardiovascular disease (CVD) and stroke produce immense health and economic burdens in the United States and globally. The Update also presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease [CHD], heart failure [HF], valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs). Since 2007, the annual versions of the Statistical Update have been cited >20 000 times in the literature. From January to July 2017 alone, the 2017 Statistical Update was accessed >106 500 times. Each annual version of the Statistical Update undergoes revisions to include the newest nationally representative data, add additional relevant published scientific findings, remove older information, add new sections or chapters, and increase the number of ways to access and use the assembled information. This year-long process, which begins as soon as the previous Statistical Update is published, is performed by the AHA Statistics Committee faculty volunteers and staff and government agency partners. This year's edition includes new data on the monitoring and benefits of cardiovascular health in the population, new metrics to assess and monitor healthy diets, new information on stroke in young adults, an enhanced focus on underserved and minority populations, a substantively expanded focus on the global burden of CVD, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the AHA's 2020 Impact Goals. Below are a few highlights from this year's Update.

Prosthesis‐specific and patient‐specific anticoagulation

Article

Jan 1992

EG Butchart

Growing importance of valvular heart disease in the elderly

Article

Dec 2016

Association Between Patient Knowledge of Anticoagulation, INR Control, and Warfarin-Related Adverse Events

Article

May 2016

Background: Whether the level of patient’s knowledge about warfarin plays any role in maintenance of therapeutic international normalized ratio (INR) is controversial. Several studies have looked at patients’ warfarin knowledge and the level of patients’ anticoagulation control (AC). Most studies had small numbers and did not use validated questionnaires. Objectives: To use the Oral Anticoagulation Knowledge (OAK) test to assess patients’ knowledge of AC and to examine associations between knowledge, INR, and adverse events. Methods: In this cross-sectional study, patients were asked to complete the OAK test. Data on clinical and demographic characteristics, INR values, and thrombosis or bleeding events during the preceding 1 year period were collected. Associations between OAK scores, patient characteristics, proportion of therapeutic INRs, and bleeding/thrombosis events were assessed. Results: A total of 225 patients completed the OAK test. Mean (SD) age was 70 (13.4) years, 53% were male, and 75% were on warfarin for >3 years. Over the preceding year, 57.3% of INRs were therapeutic, and there were 22 bleeding and 6 thrombotic events. The mean OAK score was 12/20 (passing score = 15/20); 64% of patients failed the OAK test. Predictors of passing the OAK test were younger age (P = .01) and higher level of education (P = .03). There was no association between OAK score and proportion of therapeutic INRs, or OAK score and bleeding or thrombosis events. Conclusion: We used the OAK test to assess patients’ AC knowledge. Results suggests that while younger and more educated patients were more likely to pass the OAK test, the OAK test results may not predict INR control or occurrence of bleeding or thrombotic events.

Knowledge Regarding Oral Anticoagulant Therapy among Patient with Mechanical Heart Valve Replacement: A Cross-Sectional Study in

Abstract and Figures

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