Effect Of Simvastatin On Cardiac Hypertrophy And Left Ventricular Function In Patients With Essential Hypertension

ObjectiveTo evaluate the effects of Simvastatin on left ventricular hypertrophy and left ventricular function in patients with essential hypertension.MethodsUntreated patients with essential hypertension were chosen when they were diagnosed from August 2005 to September 2007. According to the admitted and exclusive criterion, they were given Telmisartan-based (80mg per day) therapy, and checked up the blood pressure each week .If the blood pressure was still higher than normal, they were administered the calcium-channel blocker,βreceptor blocker or hydrochlorothiazide (using conventional dosage); Digoxin(0.125mg per day) was added if the patients had heart failure. When the blood pressures stepped down to normal standard, that is SBP﹤140mmHg and DBP﹤90mmHg,the patients who were diagnosed with left ventricular hypertrophy by echocardiography for the first time, would be double-checked the history, the coronary artery by coronary arteriongraphy or coronary artery computer tomography , the renal artery by arteriongraphy or ultrasonography, the kidney and the adrenal gland by ultrasonography, the chest X-ray, the blood test and the urine test, in order to ruled out other diseases that can induce cardiac hypertrophy. The 42 left patients (33 male, 17 female) were final observed targets. With the consent of these patients, they were single-blindedly divided into two groups, one was control group (Group T), the other was experimental group (Group TS). Group T was given Telmisartan-based (80mg per day) therapy, Group TS was given Telmisartan-based (80mg per day) therapy plus Simvastatin(20mg per night). The chages of blood pressure, plasma lipid and left ventricular hypertrophy and left ventricular function observed by echocardiography were checked and recorded after 1 year.Continuous variables were expressed as mean±SD. Differences at baseline and follow-up in each group were compared by paired t tests. Proportions of the drug usage among the groups were compared by using chi-square test with continuity correction. The data was processed by SPSS13.0. Two sided significance tests were used throughout. p<0.05 represents statistically significant.Result1. General states in patients of essential hypertension combined with left ventricular hypertrophyWhen the experiment was over, 1 patient in Group T was ruled out because of aortic insufficientia induced by infective endocarditis. There were 18 effective cases in Group T(10 male,8 female). There were 23 effective cases in Group TS(17 male,6 female).No drug untoward reaction happened during the whole experiment.1.1. Other coexisted diseases in patients of essential hypertension combined with left ventricular hypertrophyFrom August 2005 to September 2007, there were 237 untreated patients with essential hypertension who were diagnosed with left ventricular hypertrophy by echocardiography for the first time after the blood pressures stepped down to normal standard. 195 patients were ruled out according to the exclusive criterion, which is 82.28% of all the patients of essential hypertension combined with left ventricular hypertrophy. Among them there were 136 patients excluded because of coronary heart disease, the ratio is 69.74% of all the excluded cases (57.38% of all the patients of essential hypertension combined with left ventricular hypertrophy).During the observation, 1 patient was ruled out because of aortic insufficientia induced by infective endocarditis. The 41 left patients were final observed targets, which is 17.30% of all the patients of essential hypertension combined with left ventricular hypertrophy.1.2. The state of blood pressure in these 41 cases before treatmentOf the selected cases, the systolic blood pressures(SBP) were 189.44±20.10mmHg, the diastolic blood pressures(DBP) were 100.71±16.51mmHg. The systolic blood pressures were especially high.1.3.The changes of plasma lipid in two groups before and after the treatmentAfter 1 year treatment, we observed a statistically significant reduction in total cholesterchol levels and low-density lipoprotein levels in the experimental group (Group TS) versus the control group(Group T) (p﹤0.01).2. The effects on lowing blood pressure2.1.1. The effects on lowing blood pressure in all the recruited patientsAfter 1 year treatment, we observed a statistically significant reduction in systolic blood pressures(SBP 189.44±20.10mmHg) levels and diastolic blood pressures(DBP 100.71±16.51mmHg) levels in all the recruited patients versus pretreatment(133.07±13.84mmHg and 79.07±8.00mmHg, respectively)(p﹤0.01).2.1.2. The combination of other depressurization drugsThe efficient ratio of monotelmisartan was 17.07%, the ratio of the combination of 2 kinds of depressurization drugs was 41.46%, the ratio of the combination of 3 kinds of depressurization drugs was 41.46%.The most widely used as combination of other depressurization drugs was calcium-channel blocker(CCB)(the rate is 68.29%), the next two were hydrochlorothiazide (the rate is 36.59%) andβreceptor blocker(the rate is 31.71%) .2.2.1. The effects on lowing blood pressure in control group (Group T)After 1 year treatment, we observed a statistically significant reduction in systolic blood pressures(SBP 187.17±20.21mmHg) levels and diastolic blood pressures(DBP 99.83±15.95mmHg) levels in Group T versus pretreatment (139.22±16.34mmHg and 79.06±8.22mmHg, respectively)(p﹤0.01).2.2.2. The combination of other depressurization drugs in Group TThe efficient ratio of monotelmisartan was 22.22%, the ratio of the combination of 2 kinds of depressurization drugs was 33.33%, the ratio of the combination of 3 kinds of depressurization drugs was 44.44%.The most widely used as combination of other depressurization drugs was calcium-channel blocker(CCB)(the rate is 66.67%), the next two were hydrochlorothiazide (the rate is 38.89%) andβreceptor blocker(the rate is 16.67%) .2.3.1. The effects on lowing blood pressure in experimental group (Group TS)After 1 year treatment, we observed a statistically significant reduction in systolic blood pressures(SBP 191.22±20.29mmHg) levels and diastolic blood pressures(DBP 101.39±17.26mmHg) levels in Group T versus pretreatment (128.26±9.33mmHg and 79.09±8.02mmHg, respectively)(p﹤0.01).2.3.2. The combination of other depressurization drugs in Group TSThe efficient ratio of monotelmisartan was 4.35%, the ratio of the combination of 2 kinds of depressurization drugs was 47.83%, the ratio of the combination of 3 kinds of depressurization drugs was 47.83%.The most widely used as combination of other depressurization drugs was calcium-channel blocker(CCB)(the rate is 69.57%), the next two wereβreceptor blocker(the rate is 43.48%) and hydrochlorothiazide (the rate is 34.78%).2.4.1. The comparison of the effects on lowing blood pressure between control group(Group T) and experimental group (Group TS) Telmisartan-based treatment plus Simastatin can statistically significantly reducesystolic blood pressure(p<0.05).2.4.2. The comparison of the combination of other depressurization drugs between control group(Group T) and experimental group (Group TS)There was no statistically significant difference between Group T and Group TS referring to the combination of other depressurization drugs(p>0.05). 3. The effect of Telmisartan on cardiac hypertrophy and left ventricular function3.1. The effect of Telmisartan on cardiac hypertrophyAfter 1 year Telmisartan-based treatment, we observed a statistically significant reduction in interventricular septum(IVS), left ventricular mass(LVM), left ventricular mass index(LVMI) (P<0.05) versus pretreatment, which signified the reversing of left ventricular hypertrophy. But There was no significant difference in left ventricular inner diameter(LVDd) and left ventricular posterior wall(LVPW) (p>0.05).3.2. The effect of Telmisartan on left ventricular systolic functionAfter 1 year Telmisartan-based treatment, ejection fraction(EF(66.83±11.62)%) dropped to (65.67±10.63)%, there was no statistically significant improvement on left ventricular systolic function(p>0.05).3.3. The effect of Telmisartan on left ventricular diastolic functionAfter 1 year Telmisartan-based treatment, both left atrial inner diameter(LA) and the ratio of E/A increased, though neither had a statistically significant meaning(p>0.05).3.4. The correlation of the changes between the index of cardiac remolding and the blood pressureThe changes of left ventricular mass (LVM) positively correlated with the changes of diastolic blood pressure(DBP).Pearson's product-moment correlation coefficient r=0.645(p<0.01).4. The effect of Simvastatin on cardiac hypertrophy and left ventricular function4.1. The effect of Simvastatin on cardiac hypertrophyAfter 1 year Telmisartan-based plus Simvastatin treatment, we observed a statistically significant reduction in interventricular septum(IVS), left ventricular inner diameter(LVDd), left ventricular posterior wall(LVPW), left ventricular mass(LVM), left ventricular mass index(LVMI) (p<0.05)versus pretreatment, which signified the reversing of left ventricular hypertrophy.4.2. The effect of Simvastatin on left ventricular systolic functionAfter 1 year Telmisartan-based plus Simvastatin treatment, ejection fraction(EF 57.50±16.41%) went up to (65.43±11.60)%, there was a statistically significant improvement on left ventricular systolic function(p<0.05).4.3. The effect of Simvastatin on left ventricular diastolic functionAfter 1 year Telmisartan-based plus Simvastatin treatment, The left atrial inner diameter(LA) decreased statistically and significantly(P<0.05). While the ratio of E/A declined all the same, though there was no statistically significant meaning(p>0.05).4.4. The correlation of the changes between the index of cardiac remolding and the blood pressureThe changes of interventricular septum (IVS) positively correlated with the changes of systolic blood pressures (SBP). Pearson's product-moment correlation coefficient r=0.554(p<0.01).4.5. The comparison of the effect on cardiac hypertrophy and left ventricular function between control group(Group T) and experimental group (Group TS)Treatment plus Simvastatin can statistically significantly reduce interventricular septum(IVS), left ventricular mass(LVM), left ventricular mass index(LVMI) (p<0.05), reverse cardiac hypertrophy; increase left ventricular ejection fraction(EF) (P<0.01), improve left ventricular systolic function, reduce left ventricular inner diameter(LVDd) (p<0.01), but the ratio of E/A, indicating the left ventricular diastolic function, still declined, there was no significant difference versus pretreatment(p>0.05).Conclusion1. Conventional hypertension treatment plus Simvastatin can perfectly reduce systolic blood pressure in patients with essential hypertension.2. Simvastatin has effects on reversing left ventricular hypertrophy and improving the left ventricular systolic function.3. Simvastatin might have nothing to do with reversing left ventricular diastolic function in hypertensive patients.