Short QT interval and atrial fibrillation in patients without structural heart disease.
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Atrial Fibrillation↗
Biomedical subjects
Bojan Vrtovec
Publications and source records attributed to Bojan Vrtovec.
Statin-associated QTc interval shortening as prognostic indicator in heart transplant recipients.
Statin treatment promotes survival after cardiac transplantation by reducing cholesterol levels, allograft rejection, and transplant coronary artery disease. Analysis of data from 114 heart transplant recipients (including 86 treated with statins for < or =1 year post-transplantation) revealed that statins were associated with shortened corrected QT intervals (QTc), reduced low-density lipoprotein cholesterol, and reduced transplant coronary artery disease incidence at 1 year and improved survival at 5 years. Statin-associated QTc shortening thus appears to be a favorable prognostic sign after transplantation.
Adult↗
QTc interval prolongation predicts postoperative mortality in heart failure patients undergoing surgical revascularization.
QTc interval prolongation is associated with increased mortality rates in patients with advanced heart failure. We investigated the predictive value of prolonged QTc interval in 567 patients with heart failure who were undergoing coronary artery bypass graft surgery The patients were in New York Heart Association class III or IV, with left ventricular ejection fractions of 0.40 or less. Before surgery, the QT interval duration was measured in leads II and V4 of the standard electrocardiogram and corrected by use of the Bazett formula. The QTc interval was prolonged (>440 msec) in 243 patients (43%) and normal in 324 (57%). The 2 study groups--prolonged QTc versus normal QTc--did not differ in terms of age (62 +/- 11 years vs 64 +/- 10 years, P=0.65), sex (80% male vs 76% male, P=0.31), ejection fraction (0.29 +/- 0.08 vs 0.29 +/- 0.09, P=0.72), hypertension (82% vs 78%, P=0.34), or diabetes (11% vs 7%, P=0.10). Within 1 month after coronary artery bypass grafting, 22 of 243 patients (9.1%) in the prolonged QTc group died, compared with 5 of 324 in the normal QTc group (1.5%) (P=0.0001). QTc interval prolongation was the only independent predictor of postoperative mortality on multivariate analysis (P=0.002). We conclude that patients with heart failure and preoperative QTc interval prolongation have increased mortality rates after coronary artery bypass grafting.
Coronary Artery Bypass↗
Prognostic value of the QTc interval after cardiac transplantation.
BACKGROUND: Although QTc interval prolongation is considered a risk factor for adverse outcome in the non-transplant population, its predictive value in heart transplant recipients has not been studied yet. This study was conducted to determine whether prolonged QTc interval is a useful predictor of outcome in heart transplant recipients. METHODS: QTc intervals were measured in 587 adult patients who underwent heart transplantation between May 1982 and January 2002. QT interval duration was determined by averaging 3 consecutive beats in all 12 leads of the standard electrocardiogram (ECG) and corrected with the Bazett formula. Baseline ECGs were obtained within 7 days after transplantation; follow-up ECGs were recorded annually at the time of routine angiography. Patients were followed over 85 +/- 65 months (range, 3 months-17 years). RESULTS: During follow-up, 241 patients died. The mean QTc interval duration in these patients was comparable with that in the remaining cohort (432 +/- 26 msec vs 423 +/- 25 msec, p = 0.07). However, patients with a relative increase in QTc duration of >or=10% between the first and second post-transplantation year (DeltaQTc >or= 10%) had a 6.86-times higher risk of dying compared with patients with DeltaQTc < 10% (p = 0.0005). Furthermore, DeltaQTc >or= 10% was the only independent predictor of long-term mortality on multivariate analysis (p = 0.0008). CONCLUSIONS: A relative increase in QTc interval duration of >or=10% between the first and second post-transplantation year is a strong, independent predictor of mortality in heart transplant recipients.
Adult↗
Chromium supplementation shortens QTc interval duration in patients with type 2 diabetes mellitus.
BACKGROUND: We investigated the potential effects of chromium supplementation on QTc interval duration in type 2 diabetic patients. METHODS: Of 60 patients with type 2 diabetes mellitus, 30 were randomly assigned to group A, and 30 to group B. Group A received 1000 microg of chromium picolinate (CrPic) daily for 3 months, followed by placebo in the next 3 months; group B was treated with placebo for the first 3 months and CrPic in the next 3 months. At each visit, QT interval was measured on a standard electrocardiogram by averaging 3 consecutive beats in leads II and V4 and corrected for heart rate with Bazett formula. RESULTS: Although baseline QTc interval was similar in both groups (422 +/- 34 milliseconds in group A vs 425 +/- 24 milliseconds in group B, P = .77), QTc interval at 3 months was shorter in group A (406 +/- 35 milliseconds) than in group B (431 +/- 26 milliseconds, P = .01). In the following 3 months, QTc interval shortened in group B but not in group A, which resulted in a comparable QTc interval duration of both groups at the end of the study (414 +/- 28 milliseconds in group A vs 409 +/- 22 milliseconds in group B, P = .50). Apart from body mass index (31.4 +/- 4.2 kg/m2 in patients with QTc shortening vs 28.7 +/- 4.2 kg/m2 in patients without QTc shortening, P = .03), none of the clinical and laboratory variables predicted QTc interval shortening in our patient cohort. CONCLUSIONS: Short-term chromium supplementation shortens QTc interval in patients with type 2 diabetes mellitus.
Chromium↗
Atorvastatin therapy increases heart rate variability, decreases QT variability, and shortens QTc interval duration in patients with advanced chronic heart failure.
BACKGROUND: Although statins decrease the incidence of ventricular arrhythmias in patients with atherosclerotic heart disease, their potential antiarrhythmic effects in heart failure remain undefined. METHODS AND RESULTS: Of 80 heart failure patients enrolled, 40 were randomized to receive atorvastatin (statin group); the remaining 40 served as controls. At baseline and after 3 months, we measured heart rate variability (HRV), QT variability (QTV), and QTc interval using interactive high-resolution electrocardiogram analysis. The 2 groups did not differ in baseline HRV standard deviation of normal-to-normal intervals (SDNN) (RR): 24.6 +/- 2.8 ms in statin group versus 24.8 +/- 3.1 ms in controls, P = .72; square root of the mean of squared differences between successive intervals (rMSSD) (RR): 21.2 +/- 2.7 ms versus 21.7 +/- 2.9 ms, P = .43), QTV SDNN (QT): 6.4 +/- 1.5 ms versus 6.4+/-1.7, P = .96; rMSSD QT): 9.0 +/- 2.4 ms versus 8.7 +/- 2.9 ms, P = .65, and QTc interval 450 +/- 30 ms versus 446 +/- 27 ms, P = .59. At 3 months, the statin group displayed higher HRV SDNN RR): 27.2 +/- 4.9 ms versus 24.4 +/- 2.8 ms in controls, P = .003; rMSSD RR: 24.7 +/- 4.2 ms versus 21.3 +/- 5.6 ms, P = .004, lower QTV SDNN (QT): 5.1 +/- 1.9 ms versus 6.5 +/- 2.1, P = .004; rMSSD (QT): 6.6 +/- 2.8 ms versus 8.8 +/- 3.1 ms, P = .002, and shorter QTc interval 437 +/- 29 ms versus 450 +/- 25 ms, P = .03 than the control group. CONCLUSIONS: Atorvastatin increases HRV, decreases QTV, and shortens QTc interval, and may thereby reduce the risk of arrhythmias in patients with advanced heart failure.
Anti-Arrhythmia Agents↗
Factors predicting 10-year survival after heart transplantation.
BACKGROUND: We sought to identify factors predictive of long-term (>10-year) survival in heart transplant (HTx) recipients. METHODS: Four hundred fifteen adult patients underwent HTx at our institution between August 1982 and May 1997. The 158 patients who survived >10 years (Group A) and the 116 patients who died between 2 and 6 years (Group B) of HTx were compared in terms of gender, gender mismatch, ethnicity, age, height, weight, United Network for Organ Sharing status, type of induction therapy (OKT3 or anti-thymocyte globulin), infections (bacterial, viral, fungal and protozoal), cytomegalovirus (CMV) status, CMV mismatch, diabetes mellitus, hypertension and incidence of rejection episodes and transplant coronary artery disease within 2 years of HTx. RESULTS: Group A (135 men, 23 women; mean age 48 +/- 11 years) had significantly fewer post-HTx rejection episodes and viral, bacterial, fungal and total infections than did Group B (95 men, 21 women; mean age 49 +/- 12 years). Group A also had a significantly lower mean donor age, a lower incidence of pre-HTx diabetes, and a lower mean cholesterol level 1 year after HTx. In a multivariate analysis, fewer bacterial infections and rejection episodes after HTx, the absence of pre-HTx diabetes, and lower donor age were associated with longer survival. CONCLUSIONS: Pre-HTx diabetes, donor age and incidences of infection and rejection within 2 years of HTx predict long-term (>10-year) survival. Better control of infection and rejection during the first 2 years after HTx may improve survival.
Age Factors↗
Is bridging to transplantation with a left ventricular assist device a risk factor for transplant coronary artery disease?
BACKGROUND: Left ventricular assist device (LVAD) support is associated with coagulopathy, bleeding, increased blood transfusion, and increased anti-HLA antibody production. Increased anti-HLA antibody production is associated with early transplant rejection, transplant coronary artery disease (CAD), and decreased post-transplant survival rates. We asked whether bridging to transplantation with an LVAD increases the risk of transplant CAD. METHODS: We reviewed data for all adults (>18 years old) who underwent heart transplantation at our institution between 1988 and 2000. After exclusion of transplant recipients who survived <3 years, we divided the remaining cohort into 2 groups: those bridged to transplantation with LVADs (mean duration of support, 149 +/- 107 days, n = 29) and those in United Network for Organ Sharing Status 1 bridged to transplantation without LVADs (controls, n = 86). We compared groups in terms of disease cause, age, sex, donor age, panel-reactive antibody testing, crossmatching, pre- and post-transplant cholesterol concentrations, diagnosis of diabetes mellitus or treated hypertension, infections, calcium channel blocker use, transplant rejection, ischemic time, cytomegalovirus infection, pre-transplant transfusion, and incidence of transplant CAD (defined as any coronary lesion identified by coronary angiography). We considered p < 0.05 to be significant. RESULTS: The bridged and control groups were similar in all respects except mean ischemic time (217 +/- 58 minutes vs 179 +/- 67 minutes, p = 0.007), post-transplant cholesterol concentration (212 +/- 55 mg/dl vs 171 +/- 66 mg/dl, p = 0.007), and pre-transplant transfusion incidence (100% vs 22%, p < 0.001). The incidence of transplant CAD was similar in both groups during a 3-year follow-up period (28% vs 17%, p = 0.238) and during total follow-up (34% vs 35%, p = 0.969). Multivariate logistic regression analysis identified cholesterol concentration at 1 year after transplantation as a significant predictor of CAD at 3 years after heart transplantation (p = 0.0029, odds ratio = 0.984). CONCLUSIONS: Bridging to transplantation with an LVAD does not increase the risk of transplant CAD. Nevertheless, aggressive prophylactic therapy to minimize potential risk factors for transplant CAD, such as increased cholesterol concentration, is warranted in all transplant recipients.
Adult↗
Nitric oxide versus prostaglandin E1 for reduction of pulmonary hypertension in heart transplant candidates.
BACKGROUND: We sought to directly compare the effects of prostaglandin E1 (PGE1) and nitric oxide (NO) in testing for pulmonary hypertension reversibility in heart transplant candidates. METHODS: We included 19 heart transplant candidates who fulfilled at least 1 of 3 criteria: pulmonary vascular resistance (PVR) of >4 Wood units; transpulmonary gradient (TPG) of >12 mmHg; or systolic pulmonary artery pressure (PAP) of >60 mmHg. Patients randomly received either PGE1 (0.05, 0.2 and 0.5 microg/kg/min) or NO (40, 60 and 80 ppm) and were crossed-over to the second medication after receiving the maximal dose of the first. RESULTS: With PGE1, TPG decreased by 21% (baseline 20.3 +/- 6.8 mmHg; final 16.0 +/- 7.0 mmHg) compared to a 34% decrease with NO (baseline 20.8 +/- 6.2 mmHg; final 13.8 +/- 5.4 mmHg) (p = 0.13). PVR decreased by 42% with PGE1 (baseline 6.2 +/- 4.0 Wood units; final 3.6 +/- 1.8 Wood units) and by 47% with NO (baseline 6.0 +/- 3.9 Wood units; final 3.2 +/- 1.6 Wood units) (p = 0.87). Mean systemic pressure decreased with PGE1 (baseline 76.1 +/- 10.5 mmHg; final 69.4 +/- 12.2 mmHg; -9%) but not with NO administration (baseline 70.2 +/- 14.7 mmHg; final 71.6 +/- 10.9 mmHg; +2%) (p = 0.01). TPG was lowered to <12 mmHg in 14 patients. Of these, 6 (46%) responded to both PGE1 and NO, 4 (27%) responded only to PGE1, and 4 (27%) responded only to NO. CONCLUSIONS: The effects of PGE1 and NO on pulmonary hypertension are comparable, with PGE1 having more systemic hypotensive effects. Due to variability of patient responses, we recommend multiple rather than single-agent pharmacologic testing for the reversibility of pulmonary hypertension.
Administration, Inhalation↗
Survival, graft atherosclerosis, and rejection incidence in heart transplant recipients treated with statins: 5-year follow-up.
BACKGROUND: Few studies have examined the long-term benefits of statin treatment in heart transplant recipients. METHODS: In this observational study, we retrospectively reviewed data pertaining to 5-year follow-up of patients who underwent heart transplantation between 1993 and 1996 and who survived the first 30 days after transplantation. Patients were assigned to groups according to whether or not they received pravastatin after transplantation, and then compared with regard to transplant rejection, transplant coronary artery disease, and survival. RESULTS: Ninety-one patients received pravastatin after transplantation, whereas 37 did not receive any statins and served as controls. Pravastatin did not affect the overall incidence of rejections or number of rejection episodes. Hemodynamically significant rejection episodes occurred in 5 patients (5%) in the pravastatin group and 4 patients (11%) in the control group. Thus, pravastatin treatment apparently reduced the incidence of hemodynamically significant rejection episodes by 50% (p = 0.04). Transplant coronary artery disease (CAD) occurred in 10 patients (11%) in the pravastatin group and 9 patients (24%) in the control group. Treatment with pravastatin significantly reduced the incidence of transplant CAD (p = 0.05). Three- and 5-year survival rates in the pravastatin group were significantly better than in the control group (87% vs 68% and 82% vs 58%, respectively; p = 0.009). CONCLUSIONS: Pravastatin therapy offers long-term benefits to heart transplant recipients. It improves 5-year survival, lowers the risk of transplant CAD, and lowers the incidence of hemodynamically significant rejection episodes.
Adolescent↗
Coronary artery disease alters ventricular repolarization dynamics in type 2 diabetes.
Ventricular repolarization dynamics (VRD) is an important predictor of outcome in diabetes. We examined the potential impact of coronary artery disease (CAD) on VRD in type 2 diabetic patients. We recorded 5-minute high-resolution resting electrocardiograms in 38 diabetic patients undergoing elective coronary angiography, and in 38 age- and gender-matched apparently healthy subjects (controls). Using leads-I and -II, time-domain indices of VRD were calculated. Coronary angiography was regarded as positive if >/= 50% stenosis was found. Angiography was positive in 21 diabetic patients (55%). Patients with CAD had a significantly higher degree of VRD than controls (SDNN(QT): 15.81 +/- 7.22 ms versus 8.94 +/- 6.04 ms; P < 0.001, rMSSD(QT): 21.02 +/- 7.07 ms versus 11.18 +/- 7.45 ms; P < 0.001). Ventricular repolarization dynamics in diabetic patients with negative angiograms did not differ from VRD in controls (SDNN(QT): 8.94 +/- 6.04 ms versus 7.44 +/- 5.72 ms; P = 0.67, rMSSD(QT): 11.18 +/- 7.45 ms versus 10.22 +/- 5.35 ms; P = 0.82). CAD increases VRD in patients with type 2 diabetes. Therefore, changes in ventricular repolarization in diabetic patients may be due to silent CAD rather than due to diabetes per se.
Case-Control Studies↗
Prolonged QTc interval and high B-type natriuretic peptide levels together predict mortality in patients with advanced heart failure.
BACKGROUND: The role of QTc interval prolongation in heart failure remains poorly defined. To better understand it, we analyzed the QTc interval duration in patients with heart failure with high B-type natriuretic peptide (BNP) levels and analyzed the combined prognostic impact of prolonged QTc and elevated BNP. METHODS AND RESULTS: QTc intervals were measured in 241 patients with heart failure who had BNP levels >400 pg/mL. QT interval duration was determined by averaging 3 consecutive beats through leads II and V4 on a standard 12-lead ECG and corrected by using the Bazett formula. QTc intervals were prolonged (>440 ms) in 122 (51%) patients and normal in 119 (49%). The BNP levels in these 2 groups were not significantly different (786+/-321 pg/mL in the prolonged QTc group versus 733+/-274 pg/mL in the normal QTc group, P=0.13). During 6 months of follow-up, 46 patients died, 9 underwent transplantation, and 17 underwent left ventricular assist device implantation. The deaths were attributed to pump failure (n=24, 52%), sudden cardiac death (n=18, 39%), or noncardiac causes (n=4, 9%). Kaplan-Meier survival rates were 3 times higher in the normal QTc group than in the prolonged QTc group (P<0.0001). On multivariate analysis, prolonged QTc interval was an independent predictor of all-cause death (P=0.0001), cardiac death (P=0.0001), sudden cardiac death (P=0.004), and pump failure death (P=0.0006). CONCLUSIONS: Prolonged QTc interval is a strong, independent predictor of adverse outcome in patients with heart failure with BNP levels >400 pg/mL.
Aged↗
Outcomes in patients with low left ventricular ejection fraction after heart transplantation.
OBJECTIVES: Low left ventricular ejection fraction (EF) after heart transplantation (HT) is considered an ominous sign. We reviewed our database in order to determine outcomes in patients with low EF after HT and to identify a subset of patients who would benefit from immediate retransplantation. METHODS: We identified 825 patients who underwent HT at our institution between December 1983 and July 1999. Of these, 81 patients (70 men, 11 women; age, 48+/-12 years) had low (<35%) EF as determined by radionuclide ventriculography. Post-transplantation survival; duration of low-EF episodes (>2 years vs. <2 years); and incidence of transplant rejection, infection, and transplant coronary artery disease (CAD) were determined for these patients. RESULTS: On average, low EF developed 800+/-1029 days after HT and lasted 550+/-756 days until improvement, repeat HT, or death of the patient. Actuarial survival was 79% at 1 year, 55% at 3 years, and 46% at 5 years. Shorter (<2-year) episodes of low EF tended to have an earlier onset than prolonged (>2-year) episodes (656 days vs. 1341 days) (P=0.014). Patients with prolonged episodes (n=17) survived longer than patients with shorter episodes (n=64) (2247 days vs. 1266 days) (P=0.002). The incidence of hemodynamically significant rejection was lower in the prolonged low-EF group (6% [1/17] vs. 26% [17/64]) (P=0.03). The incidence of infection (31% vs. 53%) and incidence of transplant CAD (47% vs. 39%) did not differ significantly between the prolonged and shorter low-EF groups. CONCLUSIONS: Low EF after HT, especially with later onset, is not associated with poor survival and is not related to hemodynamically significant rejection. These data further indicate that the presence of low EF even in the setting of CAD is not by itself an indication for repeat HT.
Adult↗
Left ventricular assist devices: an alternative to medical therapy for end-stage heart failure.
Although aggressive medical therapy and ultimately cardiac transplantation have long been the therapeutic mainstays for patients with end-stage heart failure, the left ventricular assist device (LVAD), which was originally used clinically as a bridge to transplantation, may also be used as destination therapy. LVAD therapy for selected patients has been shown in the REMATCH trial to be superior to medical therapy in ameliorating symptoms and improving outcome in patients with terminal heart failure. LVAD therapy has also proved useful in improving native heart function by neuroendocrine modulation and reverse remodeling. Furthermore, current evidence suggests that when LVAD therapy is utilized to improve ventricular function, it may be further enhanced when combined with aggressive medical therapy.
Clinical Trials as Topic↗
Intravenous milrinone in treatment of advanced congestive heart failure.
Phosphodiesterase inhibitors such as milrinone can relieve symptoms and improve hemodynamics in patients with advanced congestive heart failure. We retrospectively evaluated the hemodynamic and clinical outcomes of long-term combination therapy with intravenous milrinone and oral beta-blockers in 65 patients with severe congestive heart failure (New York Heart Association class IV function and ejection fraction <25%) refractory to oral medical therapy. Fifty-one patients successfully began beta-blocker therapy while on intravenous milrinone. Oral medical therapy was maximized when possible. The mean duration of milrinone treatment in this combination-treatment group was 269 days (range, 14-1,026 days). Functional class improved from IV to II-III with milrinone therapy. Twenty-four such patients tolerated beta-blocker up-titration and were successfully weaned from milrinone. Sixteen patients (31%) died while receiving combination therapy; one died of sudden cardiac death (on treatment day 116); the other 15 died of progressive heart failure or other complications. Hospital admissions during the previous 6 months and admissions within 6 months after milrinone initiation stayed the same. Meanwhile, the total number of hospital days decreased from 450 to 380 (a 15.6% reduction), and the mean length of stay decreased by 1.4 days (a 14.7% reduction). We conclude that 1) milrinone plus beta-blocker combination therapy is an effective treatment for heart failure even with beta-blocker up-titration, 2) weaning from milrinone may be possible once medications are maximized, 3) patients' functional status improves on the combination regimen, and 4) treatment-related sudden death is relatively infrequent during the combination regimen.
Adrenergic beta-Antagonists↗
Biventricular support with the Jarvik 2000 axial flow pump: a feasibility study.
Patients with congestive heart failure who are supported with a left ventricular assist device (LVAD) may experience right ventricular dysfunction or failure that requires support with a right ventricular assist device (RVAD). To determine the feasibility of using a clinically available axial flow ventricular assist device as an RVAD, we implanted Jarvik 2000 pumps in the left ventricle and right atrium of two Corriente crossbred calves (approximately 100 kg each) by way of a left thoracotomy and then analyzed the hemodynamic effects in the mechanically fibrillated heart at various LVAD and RVAD speeds. Right atrial implantation of the device required no modification of either the device or the surgical technique used for left ventricular implantation. Satisfactory biventricular support was achieved during fibrillation as evidenced by an increase in mean aortic pressure from 34 mm Hg with the pumps off to 78 mm Hg with the pumps generating a flow rate of 4.8 L/min. These results indicate that the Jarvik 2000 pump, which can provide chronic circulatory support and can be powered by external batteries, is a feasible option for right ventricular support after LVAD implantation and is capable of completely supporting the circulation in patients with global heart failure.
Animals↗
Brain natriuretic peptide levels and response to cardiac resynchronization therapy in heart failure patients.
The authors used brain natriuretic peptide (BNP) as a reliable marker to identify nonresponders to cardiac resynchronization therapy (CRT) in patients with advanced heart failure. The study included 70 patients with left ventricular dysfunction (mean ejection fraction, 21+/-4%) and left bundle branch block (QRS duration, 164+/-25 milliseconds) treated with CRT. The authors reviewed data on New York Heart Association functional class, baseline ejection fraction, sodium, creatinine, QRS duration, and BNP levels 3 months before and after CRT therapy. The authors compared results of 42 patients who survived (973+/-192 days) after CRT implantation (responders) to those of 28 patients (nonresponders) who either expired (n=21) or underwent heart transplantation (n=5) or left ventricular assist device implantation (n=2) after an average of 371+/-220 days. Mean BNP levels after 3 months of CRT decreased in responders from 758+/-611 pg/mL to 479+/-451 pg/mL (P=.044), while in nonresponders there was increase in BNP levels from 1191+/-466 pg/mL to 1611+/-1583; P=.046. A rise in BNP levels was associated with poor response (death or need for transplantation or left ventricular assist device and impaired long-term outcome), which makes it a good predictor to identify such patients.
Aged↗