BACKGROUND: Generic drugs are bioequivalent to their brand-name counterparts; however, concerns still exist regarding the effectiveness and safety of generic drugs because of small sample sizes and short follow-up time in most studies. The purpose of this study was to evaluate the long-term antihypertensive efficacy, cost-effectiveness and cardiovascular outcomes of generic drugs compared with brand-name drugs. METHODS: In a multicenter, community-based study including 7955 hypertensive patients who were prospectively followed up for an average of 2.5 years, we used the propensity-score-matching method to match the patients using brand-name drugs to those using generic drugs in a ratio of 1:2, 2176 patients using brand-name drugs and 4352 patients using generic drugs. RESULTS: There were no significant differences between generic drugs and brand-name drugs in blood pressure (BP)-lowering efficacy, BP control rate, and cardiovascular outcomes including coronary heart disease and stroke. The adjusted mean (95% confidence interval [CI]) of systolic BP (SBP)-lowering was -7.9 mmHg (95% CI, -9.9 to -5.9) in the brand-name drug group and -7.1 mmHg (95% CI, -9.1 to -5.1) in the generic drug group after adjusting for age, sex, body mass index, number of antihypertensive drugs and traditionally cardiovascular risk factors. Among patients aged <60 years, brand-name drugs had a higher BP control rate (47% vs. 41%; P = 0.02) and a greater effect in lowering SBP compared with generic drugs, with the between-group difference of 1.5 mmHg (95% CI, 0.2-2.8; P = 0.03). BP control rate was higher in male patients using brand-name drugs compared with those using generic drugs (46% vs. 40%; P = 0.01). Generic drugs treatment yielded an average annual incremental cost-effectiveness ratio of $315.4 per patient per mmHg decrease in SBP compared with brand-name drugs treatment. CONCLUSIONS Our data suggested that generic drugs are suitable and cost-effective in improving hypertension management and facilitating public health benefits, especially in low- and middle-income areas.
Aged ; Antihypertensive Agents/therapeutic use* ; Blood Pressure ; China ; Drugs, Generic/therapeutic use* ; Humans ; Male ; Prospective Studies

Speckle tracking echocardiography (STE) has been applied to the evaluation of cardiac contraction dysfunction. However, there were few studies on alteration of global and regional STE parameters in the process of myocardial hypertrophy and heart failure. In this study, STE was applied to evaluate the global and regional cardiac function under heart failure and hypertrophy in the mice model of pressure overload. Adult mice were subjected to mild or severe aortic banding with a 25 Gauge (G) or 27 G needle. After surgery, STE and conventional echocardiography were used in the sham group (n=10), mild trans-aortic banding (TAB) group (n=14) and severe TAB group (n=10) for 8 weeks. The results showed that the mice subjected to severe TAB showed a significant change in fractional shortening (FS), left ventricular (LV) mass, and left ventricular end diastolic diameter (LVEDD) (P<0.05 for each). Meanwhile, there were no significant differences in FS and LVEDD between the sham group and mild TAB group during the experimental procedures (P>0.05 for both). STE analysis revealed that longitudinal strain (LS) was significantly decreased in the severe TAB group as compared with the sham and mild TAB groups (P<0.05 for both) from the postoperative week 1. LS in the mild TAB group was reduced as compared to the sham group (P<0.05). Radial strain (RS) and circumferential strain (CS) were significantly decreased in the severe TAB group as compared to the sham group and the mild TAB group (P<0.05 for both) from the postoperative week 1 (P<0.05 for both). Compared to the sham group, CS in the mild TAB group maintained unchanged during the test period, and RS was reduced only on the postoperative week 6 (P<0.05). Finally, regional contraction dysfunction was analyzed in both hypertrophic and failing myocardium in longitudinal and radial directions. It was found that LS was largest in the apex region and RS was smallest in the apex region in the healthy and hypertrophic myocardium. It was also found that compared to the sham group, only base longitudinal strain in the mild TAB group was decreased. Each of regional strain in the severe TAB group was uniformly depressed in radial and longitudinal directions. It is concluded that STE has provided a non-invasive and highly feasible way to explore the global and regional contraction dysfunction in hypertrophic and heart failure myocardium in the murine model of pressure overload.
Animals ; Cardiomegaly ; physiopathology ; Disease Models, Animal ; Echocardiography ; methods ; Heart Failure ; physiopathology ; Male ; Mice ; Mice, Inbred C57BL

Abnormal enhanced transmural dispersion of repolarization (TDR) plays an important role in the maintaining of the severe ventricular arrhythmias such as torsades de pointes (TDP) which can be induced in long-QT (LQT) syndrome. Taking advantage of an in vitro rabbit model of LQT2, we detected the effects of KN-93, a CaM-dependent kinase (CaMK) II inhibitor on repolarization heterogeneity of ventricular myocardium. Using the monophasic action potential recording technique, the action potentials of epicardium and endocardium were recorded in rabbit cardiac wedge infused with hypokalemic, hypomagnesaemic Tyrode's solution. At a basic length (BCL) of 2000 ms, LQT2 model was successfully mimicked with the perfusion of 0.5 μmol/L E-4031, QT intervals and the interval from the peak of T wave to the end of T wave (Tp-e) were prolonged, and Tp-e/QT increased. Besides, TDR was increased and the occurrence rate of arrhythmias like EAD, R-on-T extrasystole, and TDP increased under the above condition. Pretreatment with KN-93 (0.5 μmol/L) could inhibit EAD, R-on-T extrasystole, and TDP induced by E-4031 without affecting QT interval, Tp-e, and Tp-e/QT. This study demonstrated KN-93, a CaMKII inhibitor, can inhibit EADs which are the triggers of TDP, resulting in the suppression of TDP induced by LQT2 without affecting TDR.
Action Potentials ; drug effects ; Animals ; Anti-Arrhythmia Agents ; pharmacology ; Arrhythmias, Cardiac ; etiology ; physiopathology ; prevention & control ; Benzylamines ; pharmacology ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; antagonists & inhibitors ; metabolism ; Electrocardiography ; Electrophysiologic Techniques, Cardiac ; Endocardium ; drug effects ; physiopathology ; Heart ; drug effects ; physiopathology ; In Vitro Techniques ; Long QT Syndrome ; complications ; Pericardium ; drug effects ; physiopathology ; Piperidines ; pharmacology ; Protein Kinase Inhibitors ; pharmacology ; Pyridines ; pharmacology ; Rabbits ; Sulfonamides ; pharmacology ; Torsades de Pointes ; etiology ; physiopathology ; prevention & control

BACKGROUND: Calcium calmodulin-dependent kinase Ⅱ (CaMKⅡ) can be more active in patients with left ventricular hypertrophy (LVH), which in turn causes phosphorylation of ryanodine receptors, resulting in inactivation and the instability of intracellular calcium homeostasis. The present study aimed to determine the effect of CaMKⅡ–ryanodine receptor pathway signaling in rabbits with left ventricular hypertrophy and triggered ventricular arrhythmia. METHODS: Forty New Zealand rabbits were randomized into four groups (10 per group): sham group, LVH group, KN-93 group (LVH+KN-93), and ryanodine group (LVH+ryanodine). Rabbits in the LVH, KN-93, and ryanodine groups were used to establish a left ventricular hypertrophy model by the coarctation of the abdominal aorta, while those in the sham group did not undergo the coarctation. After eight weeks, action potentials (APs) were recorded simultaneously in the endocardium and epicardium, and a transmural electrocardiogram (ECG) was also recorded in the rabbit left ventricular wedge model. Drugs were administered to the animals in the KN-93 and ryanodine groups, and the frequency of triggered APs and ventricular tachycardia was recorded after the rabbits were given isoprenaline (1 mol/L) and high-frequency stimulation. RESULTS: The frequency (animals/group) of triggered APs was 0/10 in the sham group, 10/10 in the LVH group, 4/10 in the KN-93 group, and 1/10 in the ryanodine group. The frequencies of ventricular tachycardia were 0/10, 9/10, 3/10, and 1/10, respectively. The frequencies of polymorphic ventricular tachycardia or ventricular fibrillation were 0/10, 7/10, 2/10, and 1/10, respectively. The frequencies of triggered ventricular arrhythmias in the KN-93 and ryanodine groups were much lower than those in the LVH group (P<0.05). CONCLUSIONS: KN-93 and ryanodine can effectively reduce the occurrence of triggered ventricular arrhythmia in rabbits with LVH. The CaMKⅡ–ryanodine signaling pathway can be used as a new means of treating ventricular arrhythmia.

OBJECTIVETo investigate the effect and potential mechanism of lysophosphatidic acid (LPA) and antiarrhythmic peptide (AAP10) on rabbit ventricular arrhythmia.

METHODSTwenty-four rabbits were randomly divided into three groups (n = 8 each): control group, LPA group and AAP10 + LPA group. Using arterially perfused rabbit ventricular wedge preparations, transmural ECG and action potentials from both endocardium and epicardium were simultaneously recorded in the whole process of all experiments with two separate floating microeletrodes. The incidence of ventricular arrhythmia post S1S2 stimulation was recorded. Protein levels of nonphosphorylated Cx43 and total Cx43 were evaluated by Western blot. The distribution of nonphosphorylated Cx43 was observed by confocal immunofluorescence microscopy.

RESULTSCompared with the control group, the QT interval, endocardial action potential duration, transmural repolarization dispersion (TDR) and incidence of ventricular arrhythmia were significantly increased and nonphosphorylated Cx43 expression was significantly upregulated in the LPA group. Compared with the LPA group, cotreatment with AAP10 can reduce the QT interval, endocardial action potential duration, TDR and incidence of ventricular arrhythmia (25.0% vs 62.5%, P < 0.01) and downregulate nonphosphorylated Cx43.

CONCLUSIONSLPA could promote the arrhythmia possibly by upregulating nonphosphorylated Cx43 and subsequent gap junction transmission inhibition. Gap junction enhancer AAP10 could attenuate the pro-arrhythmic effect of LPA probably by downregulating myocardial nonphosphorylated Cx43 expression.

Animals ; Anti-Arrhythmia Agents ; pharmacology ; Arrhythmias, Cardiac ; chemically induced ; metabolism ; physiopathology ; Connexin 43 ; metabolism ; Lysophospholipids ; adverse effects ; Oligopeptides ; pharmacology ; Rabbits

Objective The aim of this study is to observe the effect of combined amiodarone and antiarrhythmic peptide (AAP10) use on the incidence of induced ventricular arrhythmias in healed myocardial infarction (MI) rabbits. Methods Twenty Japanese rabbits underwent thoracotomy without coronary artery ligation( Sham, group A) ,the middle left circumflex branch were ligated to induce MI in 180 Japanese rabbits. Eight weeks after operation, 124 rabbits survived MI operation and were divided into four groups: control group (group B, n =31 ), amiodarone group (group C, n =31 ), AAP10 group (group D,n =31 ) and amiodarone plus AAP10 group ( group E, n =31 ). The A and B and D groups were treated with saline 2 ml/d, the C and E groups were treated with 2 ml saline containing amiodarone 100 mg· kg-1·d-1. All rabbits were examined by echocardiogram at 12 weeks after operation, then anesthetized by sodium barbital, the left wedge ventricular preparations were cannulated and artery perfused by Tyrode's solution in vitro in the absence (Group A, B and C) and presence of AAP10 (500 nmol/L, Group D and E). The volume electrocardiogram, QT Interval, QRS interval, effective refractory period (ERP), the T-peak to Tend interval ( Tp-e ), and ventricular tachycardia episodes induced by programmed stimulation were recorded.The Tp-e/QT ratio was calculated. After perfusion, gap junctions protein connexin 43 (Cx43) expression was detected by Western blot and immunofluorescence. Results The incidence of induced ventricular tachycardia episodes of group A, B, C, D, E was 0, 62. 5%, 26. 9%, 40.0%, 22. 2% respectively. The incidence of induced ventricular tachycardia episodes of group E was less than group B. The Tp-e/QT ratio in group B, C, D were greater than in group A. The Tp-e/QT ratio of group E was less than group B. The myocardial Cx43 in the group B was down-regulated and disorganized compared to group A, up-regulated in group C and E compared to group B, up-regulated in group E compared to group D. The Cx43 in the heart of group D and E were well organized than in group B and C. Conclusions The artery perfused rabbits wedge preparations with healed myocardial infarction with high incidence of induced ventricular tachycardia episodes are good platform for ventricular arrhythmias research. Combined amiodarone and AAP10 use could decrease the Tp-e/QT ratio and the incidence of induced ventricular tachycardia episodes. Amiodarone and AAP10have synergistic effects on upregulating Cx43 and preventing ventricular arrhythmias in this rabbit model of healed myocardial infarction.

Objective To study the Kv1.3 channel expression changes after CD4 + and subsets CD28null/CD28+T cells activation in peripheral blood of patients with acute coronary syndrome (ACS).Methods CD4+ T cell in 27 ACS patients and CD4+ CD28null/CD4+ CD28 + T cells in 12 out of these 27 ACS patients were isolated from peripheral blood with magnetic cell sorting.The whole-cell Kv1.3 currents for three T cells were recorded with patch-clamp technique before and 72 hours after activation by purified anti-human CD3 Interferon gamma,tumor necrosis factor alpha(TNF-α),granzyme B mRNA expression were determined by reverse transcription-PCR before and 72 hours after activation by purified anti-human CD3 in the presence or absence of recombinant Margstoxin (rMgTX,0.1,1,10 nmol/L),a specific Kv1.3 channel blocker.Results Peak Kv1.3 channel currents of CD4 + ,CD4+ CD28null,CD4+ CD28 + T cells were significantly increased and the mean Kv1.3 channel numbers per cell of these cells were increased by about 90%,60%,80% (402 ± 88 vs.752 ± 275,553 ± 328 vs.874 ± 400,392 ± 133 vs.716 ± 251,all P <0.05) after activation compared to baseline values.Baseline CD4+ CD28nullT cell numbers were about 40% more than those of CD4+ CD28+ T cell (P < 0.05) and were similar after activation (P = 0.102).The mRNA expression of interferon gamma,TNF-α and granzyme B were dose-dependently down-regulated by rMgTX.Conclusions Kv1.3 channels of peripheral CD4 + T cell and CD28null/CD28 + T cells from ACS patients significantly increased after activation and Kv1.3-specific channel blocker rMgTX could effectively abolish this effect suggesting a potential role of Kv1.3 channel blocker on plaque stabilization in ACS patients.

Objective The purpose of our study is to observe the voltage-gated potassium channel Kv1.3 expression on CD4+CD28null T cells from the peripheral blood of ACS patients by the patch clamp technique.Methods Kv1.3 potassium channels expression from 17 patients with ACS and 11 healthy agematched normal controls was detected in single cell ( CD4+ CD28null T cells and CD4 + CD28 + T cells) by fluorescence microscopy and patch clamp.Results The percent of CD4+ CD28null T cells are higher in the ACS(6.97% ± 2.05% ) than that in the controls ( 1.38% ± 0.84%, P < 0.05 ).The concentration of hsCRP is directly correlated with the number of the CD4+CD28nullT cells in the ACS ( r = 0.52, P < 0.05). The conductance[ (6.89 ± 1.17) nS vs.(3.36 ± 0.66) nS ], dens [ ( 1.95 ± 0.80) n/μm2 vs.( 1.13 ± 0.57) n/μm2] and numbers[ (574.5±97.6) n/cell vs.(280.3±55.3) n/cell] of the Kv1.3 channels on the CD4+ CD28nullT cells are significantly higher than those on the CD4 + CD28 + T cells ( all P < 0.01 ) in ACS patients, but were similar on CD4 + CD28 + T cells between ACS patients and controls.conclusion The CD4+ CD28nullT cells in the ACS and the numbers of Kv1.3 channels on the CD4 + CD28nullT cells from the ACS patients are significantly upregulated and might contribute to the pathogenesis of ACS.

OBJECTIVETo investigate the effect of KN-93, a calmodulin kinase II inhibitor, on ventricular arrhythmias in rabbits with cardiac hypertrophy.

METHODSFemale New Zealand white rabbits were randomly divided into four groups (n = 10 each): Sham; LVH; LVH + KN-92 and LVH + KN-93 group. LVH was induced by partially constricting the abdominal aorta. In Sham group, the abdominal aorta was exposed without constriction. Eight weeks later, the arterially perfused left ventricular wedge preparations were made and transmembrane action potentials (TAP) from epicardium and endocardium and transmural ECG were simultaneously recorded. Incidence of early after depolarization (EAD) and torsade de pointes (Tdp), QT interval, action potential duration (APD) and transmural depolarization dispersion (TDR) at different cycle lengths were observed under slow stimulation (2000 - 4000 ms), hypokalemic (2 mmol/L) and hypomagnesaemic (0.25 mmol/L) Tyrode's solution perfusion.

RESULTSLeft ventricular hypertrophy was detected in LVH group by echocardiography and not affected by KN-92 and KN-93. Perfused with hypokalemic, hypomagnesaemic Tyrode's solution and under slow stimulation (2000 - 4000 ms), the incidences of EAD and Tdp in Sham group, LVH group, LVH + KN-92 group (0.5 micromol/L) and LVH + KN-93 group (0.5 micromol/L) were 0/10, 10/10, 9/10, 5/10 and 0/10, 5/10, 4/10, 1/10, respectively. With 1 micromol/L KN-92 and KN-93, the incidences of EAD and Tdp in LVH + KN-92 and LVH + KN-93 group were 9/10, 3/10 and 4/10, 1/10 respectively. The QT interval, APD and TDR were not affected by KN-93.

CONCLUSIONThe calmodulin kinase II inhibitor KN-93 can effectively suppress ventricular arrhythmias in rabbits with cardiac hypertrophy by decreasing EAD.

Animals ; Arrhythmias, Cardiac ; complications ; drug therapy ; Benzylamines ; pharmacology ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; antagonists & inhibitors ; Cardiomegaly ; complications ; drug therapy ; Disease Models, Animal ; Male ; Protein Kinase Inhibitors ; pharmacology ; Rabbits ; Sulfonamides ; pharmacology

OBJECTIVETo determine current density of voltage-gated potassium channels and Kv1.3 express in T-lymphocyte derived from patients with acute coronary syndrome (ACS).

METHODSPeripheral blood mononuclear cells were collected from 12 patients with ACS and 10 control donors. Whole-cell patch clamp technique was used to record the outward K(+) currents (IK) and western blots technique was used to detect the express of Kv1.3 protein in lymphocyte.

RESULTS(1) The current density of voltage-gated potassium channel was significantly higher in ACS patients [(269 +/- 94) pA/pF] than in controls [(191 +/- 64) pA/pF, P < 0.01] while membrane capacitance was similar between the two groups. (2) Kv1.3 protein expression was also significantly increased in ACS patients than in controls (P < 0.01).

CONCLUSIONThe lymphocyte voltage-gated potassium channel is upregulated in patients with ACS suggesting a role of Kv activation in the pathophysiology of ACS.

Acute Coronary Syndrome ; metabolism ; Adult ; Aged ; Female ; Humans ; Kv1.3 Potassium Channel ; metabolism ; Male ; Middle Aged ; Patch-Clamp Techniques ; T-Lymphocytes ; metabolism