CONCLUSION
BIBLIOGRAPHY
lxvii CHAPTER FIVE
lxviii
constitute the catchment area of the study site. Furthermore, the Hausa and Fulanis have been reported to be involved in cultural puerperal practices including warm water bath and ingesting of sodium rich pap which are believed to cause fluid retention and increased cardiac output.62These practices were observed in the majority of patients in the present study.
Occupation of patients and their husbands. Majority of the PPCM patients were fulltime house wives. The occupation of husbands reflects the income earning of the family. Most of the husbands were mainly petty traders, subsistence farmers, commercial motor cyclists and fishermen. About 30 (60%) of the PPCM patients had informal education, while only 20 (40) had formal education. Thus many PPCM patients belonged to low income occupations. Majority of the control group 38 (76%) had formal education and only 12 (24%) had informal education.
PPCM has been associated with poverty.19A previous report from Kano showed that PPCM was the second most common heart disease among low income earners and absent among higher income earners.19A similar observation was made in Dakar, where majority of PPCM patients were unskilled labourers while executive, managerial and professional social classes were conspicuously free of the disease.18
In the present study 24 (48%) of PPCM patients were Primipara. In recent studies by Karaye et al, 11 and Isezuo et al, 20Primipara accounted for 14 (37%) and 20 (31%), of PPCM patients respectively.11, 20 This is in contrast to studies done in South Africa, Haiti, and Pakistan where only 20% of the study populations were primipara.45, 56, 84 The differed findings can be explained partly by early teenage marriage in the northern Nigeria. Though multiparity is the reported risk factor for PPCM, this study suggest possible role of primigravida resulting from early marriage.
The mean heart rate for PPCM patients and controls was 112.0 ± 7.4 bpm and 72.0 ± 9.0 bpm respectively. Large epidemiological studies have demonstrated that elevated heart rate is an
lxix
independent risk factor for mortality and morbidity in healthy individuals with and without hypertension and in patients with coronary artery disease (CAD), myocardial infarction, and congestive heart failure.85,86,87,88 Elevated heart rate has been found to be a more powerful predictor of later death than depressed left ventricular function.85 The mean BMI for PPCM patients and controls was 21.5 ± 2.6 kg/m2 and 24.4 ± 5.1 kg/m2 respectively. Previous studies have shown that increased BMI is associated with decreased all-cause mortality in patients with chronic heart failure.89, 90, 91 The potentially beneficial effect of being overweight or obese has been termed as the obesity paradox. Several hypotheses have been proposed to account for this paradox, including the suggestions that overweight and obese patients may have higher metabolic reserve, reduced cytokine and neuroendocrine activation, higher blood pressure, which may allow more aggressive upward titration of medication, and higher serum lipid levels.90, 91, 92 An association between higher BMI and improved survival in patients with acute decompensated heart failure has also been shown.92 Mean DBP and SBP were 60.1 ± 14.7 mmhg and 88.0 ± 20.7 mmhg respectively. The finding is similar to a previous study in Kano 3 years ago where the mean DBP and SBP were 73.7 ± 10.2 mmhg and 98.2 ± 13.7 mmhg, respectively but in contrast to what was reported from the United States of America with corresponding values of 97.3 ± 19 bpm, 72 ± 13 mmHg, 111 ± 17mmhg and South Africa with 101 ± 19.8 bpm, 75 ± 12 mmHg, 113 ± 19 mmHg. Late presentation can explain the differed findings.
The mean albumin for PPCM patients and controls was 30.5 ± 3.1 g/l and 36.2 ± 3.7 g/l respectively (p<0.0001). Poor nutrition may explain the differed findings as most of the patients in the present study were low income earners. Hypoalbuminemia is a common condition in patients with heart failure and is mainly related to the malnutrition-inflammation complex syndrome.93 Other causal factors can be involved, which include hemodilution, liver dysfunction,
lxx
increased transcapillary escape rate, renal and enteral loss.93Hypoalbuminemia may also contribute to the progression of heart failure by favoring myocardial edema, volume overload, diuretic resistance and exacerbation of oxidative stress and inflammation.93
Mean urea, creatinine and eGFR were 9.9 ± 6.2 mmol/l, 124.4 ± 84.9 µmol/l and 82.9 ± 33.8 ml/min, respectively. This finding is in contrast to what was reported from South Africa where the mean urea and creatinine were 5.2 ± 2.5mmol/l and 84.8 ± 19.8µmol/l, respectively. The renal parameters of PPCM patients suggest that some of them had impaired renal function. This could be because of late presentation with heart failure and cardiorenal syndrome. Mean CRP 68.7± 25.0mg/l with median of 6 (38-147) mg/l is in contrast to a study done in Haiti where the mean CRP of 22 PPCM patients was 144.3mg/l.34 Another study done in South Africa showed a median CRP of 10 (1-90) mg/l. This can be explained by the higher rate of infection in our community and the late presentation to the hospital.
The mean QRS duration for PPCM patients and controls was 90.6 ± 9.5 ms and 83.4 ± 6.8 ms respectively (p=0.0001). A wide QRS complex reflecting left sided intraventricular conduction delay in patients with heart failure is associated with more advanced myocardial disease, worse LV function, poorer prognosis and a higher all cause mortality rate compared with patients with a narrow QRS complex.94 The mean QTc interval for PPCM patients and controls was 426.0±43.0 and 407.0± 21.8 ms respectively (p<0.0001). Prolongation of QT interval in chronic heart failure (CHF) has been implicated as a risk factor for developing potentially life threatening ventricular tachy-arrhythmias such as sudden cardiac death.95 QTc prolongation is a predictor of mortality in CHF and may be an important adjunct in risk stratification of patients with heart failure.96
lxxi
Atrial fibrillation was observed in 18% of patients in the present study. This is similar to a value of 20.5% observed in Kano but higher than 3.1% recorded by Isezuo et al. Atrial fibrillation is the most common arrhythmias in HF. It increases the risk of thrombo-embolic complications particularly stroke and may lead to worsening of symptoms of HF.71 Atrial fibrillation by loss of atrial contribution to diastolic filling and decreased diastolic filling time in rapid AF is likely to decrease cardiac output and consequently precipitate acute heart failure.71
The echocardiographic features including LV geometry and LV systolic and diastolic function of PPCM in the present study are similar to the reports of previous studies in Kano and Sokoto.
These echocardiographic parameters were better among South African PPCM patients.92 Differences in chamber sizes may be more related to stage of the disease at presentation. Our patients present later than those in South Africa, with more advanced disease. This may explain why more than 50% of the patients in the present study had severe MR and TR. Left ventricular mural thrombus was recorded in 4% of the patients. This is lower than the values obtained from the studies done in Kano 21.8% and Sokoto 12.3%.83,79 Similarly in South Africa 12.3% of PPCM patients had LV mural thrombus.92 The low prevalence of LV thrombus in the current report might be related to high frequency of prophylactic anticoagulation which has become a popular practice since the publication of the above-mentioned earlier studies.79, 83
In the present study, mean TAPSE of PPCM patients was 12.0 ± 1.9 mm which is similar to the finding by Karaye et al 12.6 ± 4.2 mm.97TAPSE is an index that is free of geometric assumptions, and a value of ≤14 mm is associated with an adverse prognosis in patients with idiopathic or ischaemic Cardiomyopathy, as well as in patients with hypertensive heart disease.98
lxxii
In the present study significant risk factors for PPCM included warm water bath and ingestion of sodium rich pap. These customary puerperal practices particularly consumption of pap with large quantities of the local lake salt, known as “natron” or “kanwa” in local language for 40 days postpartum have been described among Hausa and Fulani ethnic groups of northwestern Nigeria.
The cultural practices are believed to improve lactation. They have however been proposed to impose extra burdens on the cardiovascular system.62