Demographics and clinical characteristics
A total of 106 patients were screened at cardiology clinic over the study period and 82 patients were selected based on inclusion and exclusion criteria.
Patients enrolled in this study were aged between 20 – 83 years and the mean (SD) age was 58.2 (14.7) years. Majority of study subjects were male (n = 43, 52.4 %) and 47.6% were female. Ethnic distribution results showed that more than half of the patients were Malay (n = 50, 61%) while 19 (23.2%) patients were Chinese followed by Indians (n =10, 12.2%) and others (n = 3, 3.7%). Regarding smoking status, 27 (32.9%), 22 (26.8%) and 33 (40.2%) were active smokers, ex-smokers, and non-smokers respectively. The mean (SD) BMI was 29.3 (5.5) kg/m2 with many patients were obese (n = 49, 59.8%) while 25 (30.5%) patients were overweight, and 8 (9.8%) patients were with normal BMI based on the WHO’s BMI categories for Asians.
Stages of hypertension at baseline among studied subjects
Among the study population, more than half of the diagnosed patients were in stage 1 hypertension (n = 52, 63.4%) followed by stage 2 (n = 22, 26.8%) and stage 3 (n = 8, 9.8%).
Comorbidities among studied subjects
Most patients had 1 comorbidity (n = 42, 51.2%) followed by 2 comorbidities (n = 25, 30.5%) and 3 comorbidities (n = 6, 7.3%). Among the study population, most of the patients had CKD (39%). Among these CKD subjects, stage 4 was the highest (n =17, 10%), stage 3b and stage 5 were next accounting for 8% and 8% respectively. Other comorbidities included type II DM (n = 51, 28.08%), dyslipidemia (n = 27, 14.84%), CAD (n = 16, 8.79%), stroke (n = 8, 4.4%), AF (n = 3, 1.65%), type I DM (n= 2, 1.1%), liver impairment and lung disease (n = 2, 1.1%).
Prescribing pattern of antihypertensive patients among study subjects
In this study, more than half of hypertensive patients were prescribed with monotherapy (n=48, 58.5%) while the rest of the patients were with combination therapy (n=34, 41.5%). Upon diagnosis, the most common first line antihypertensive agents prescribed were ACEI (n=31, 37.8%) followed by CCBs (n=24, 29.3%), beta-blockers (n=12, 14.6%), ARBs (n=10, 12.2%) and diuretics (n=5, 6.1%).
First line antihypertensive agents and initial prescribed doses
Angiotensin converting enzyme inhibitors (ACEI)
At diagnosis, more than half of the patients on ACEIs were prescribed with perindopril 4 mg OD (n = 18, 58%) followed by perindopril 8 mg OD (n = 10, 32.3%), perindopril 2 mg OD (n = 2, 6.5%) and captopril 25 mg BD (n= 1, 3.2%).
Calcium Channel Blockers (CCBs)
Amlodipine 10 mg OD and felodipine 10 mg OD were the most frequently prescribed CCB as shown in figure 1.
Beta-blockers
Most common beta-blocker prescribed at diagnosis was bisoprolol of various doses. Meanwhile, 100 mg OD was the most prescribed initial dose for atenolol as shown in figure 2.
Angiotensin II Receptor Blockers (ARBs)
Telmisartan 40 mg OD was the most common ARBs prescribed (n= 5, 45.5%) among studied subjects followed by valsartan 80 mg OD and irbesartan 150 mg OD (n= 3, 27.3%) with equal percentage.
Diuretics
The dosage regimen of hydrochlorothiazide 25 mg OD as a first line treatment was prescribed four times more than that of 12.5 mg OD as shown in figure 3.
Second line antihypertensive agents
When BP was not well-controlled, most of the patients received CCBs (n = 17, 35.4%) as a second line agent followed by ACEIs (n = 13, 27%), beta-blockers (n=9, 18.8%), ARBs (n = 4, 8.3%) and diuretics (n = 5, 10.4%) (Table 1). This study revealed that the most commonly second line antihypertensives were perindopril (ACEI) followed by amlodipine (CCB).
Combination therapies
Combinations of ACEIs + CCBs were the most common therapy that prescribed (n = 9, 26.5%) while combinations of beta-blockers + ARBs (n = 3, 8.9%) and beta-blockers+ Diuretics (n = 2, 5.9%) were the least prescribed as illustrated in figure 4.
Prescribing adherence to Malaysian CPG for management of hypertension (5th Edition), 2018
Anti-hypertensive monotherapy/ combination drugs were chosen according to stage of hypertension.
Adherence to the guideline when prescribing combination therapies (n=27, 79.41%) was seen more than in monotherapy. Non-adherence to guideline was found in 16 subjects who were categorized as stage 1 hypertension while in those with as medium/high/very high-risk stage 1 and ≥ stage 2 hypertension; 7 were found to be receiving antihypertensive not according to guideline (Table 2).
Prescribing adherence according to co-morbidities
As illustrated in figure 5, many subjects did not receive antihypertensive treatment according to co-morbidities (n = 49, 59.8 %).
Prescribing adherence according to optimization of drug therapies
As seen in table 3, overall adherence to guidelines was poor. For physicians who adhered to guideline, most of them followed the guideline when starting antihypertensive therapy (monotherapy) (n= 22, 26.8%). However, non-adherence was seen more during optimization of BP control after the initial prescriptions.
Prescribing adherence according to target BP
Non-adherence to guidelines were seen the most in diabetic subjects with concurrent CKD (n=42, 51.22%) as shown in table 4.
Prescribing adherence according to presence of contraindications
79 (96.3%) of the subjects received therapies that were adhering to guidelines were presence of contraindications.
Guideline adherence indicator (GAI) score among studied patients
Among the 82 studied patients, the median (IQR) GAI score was 40 (20). In this study, more than half (n=46, 56.1%) of the patients were not treated accordingly, while only 13 (15.9%) of the subjects were categorized as having good adherence to guidelines (Table 5).
Comparison of GAI among different demographic and clinical characteristics
The median (IQR) GAI score between female and male and between Malay and non-Malay were the same as shown in table 6.
Table 7 illustrates that the correlation between GAI score and patient’s age was very weak, and the correlation was not statistically significant (r = -0.075, P = 0.506). Similarly, patients’ BMI and GAI score were not significantly correlated (r = -0.129, P= 0.247).
Comorbidities
The median (IQR) GAI score among stroke patients is statistically higher (60 (0)) than those without stroke (median (IQR) GAI score, 40 (20)) (P = 0.038). There were no significant differences in GAI score among other co-morbidities (P > 0.05) (Table 8).
Correlation between GAI and BP control
The correlation between GAI score and SBP was inversely weak, and the correlation was statistically significant (r= -0.225, P= 0.042). Similarly, there was a weak but inverse correlation between GAI score and DBP (r = -0.281, P= 0.011) (Table 9).