[Update cardiology 2006/2007]. / Aktuelle Kardiologie 2006/2007: Jahresrückblick und Ausblick.

This article reviews advances in cardiovascular medicine published last year. The following issues are reported in detail: (1) risk factors and lifestyle, (2) computed tomography in coronary artery disease, (3) revascularization in cardiogenic shock, (4) long-term anticoagulation in venous thrombosis, (5) anemia in heart failure, (6) optimism and cardiovascular death, (7) mortality after drug-eluting stents, (8) diabetes and cardiovascular disease, (9) new guidelines atrial fibrillation, (10) dopamine agonists and cardiac valve regurgitation, (11) beta-blockers and hypertension, (12) angiotensin-converting enzyme inhibitors and aortic rupture, (13) statin therapy, (14) adherence to pharmacotherapy.

Sildenafil in the treatment of Raynaud's phenomenon resistant to vasodilatory therapy.

BACKGROUND: Vasodilatory therapy of Raynaud's phenomenon represents a difficult clinical problem because treatment often remains inefficient and may be not tolerated because of side effects. METHODS AND RESULTS: To investigate the effects of sildenafil on symptoms and capillary perfusion in patients with Raynaud's phenomenon, we performed a double-blinded, placebo-controlled, fixed-dose, crossover study in 16 patients with symptomatic secondary Raynaud's phenomenon resistant to vasodilatory therapy. Patients were treated with 50 mg sildenafil or placebo twice daily for 4 weeks. Symptoms were assessed by diary cards including a 10-point Raynaud's Condition Score. Capillary flow velocity was measured in digital nailfold capillaries by means of a laser Doppler anemometer. While taking sildenafil, the mean frequency of Raynaud attacks was significantly lower (35+/-14 versus 52+/-18, P=0.0064), the cumulative attack duration was significantly shorter (581+/-133 versus 1046+/-245 minutes, P=0.0038), and the mean Raynaud's Condition Score was significantly lower (2.2+/-0.4 versus 3.0+/-0.5, P=0.0386). Capillary blood flow velocity increased in each individual patient, and the mean capillary flow velocity of all patients more than quadrupled after treatment with sildenafil (0.53+/-0.09 versus 0.13+/-0.02 mm/s, P=0.0004). Two patients reported side effects leading to discontinuation of the study drug. CONCLUSIONS: Sildenafil is an effective and well-tolerated treatment in patients with Raynaud's phenomenon.

In-vitro comparison of aortic valve hemodynamics between aortic root remodeling and aortic valve reimplantation.

BACKGROUND AND AIM OF THE STUDY: Valve-preserving aortic replacement has become an accepted option for patients with aortic valve regurgitation and aortic dilatation. The relative role of root remodeling versus valve reimplantation inside a vascular graft has been discussed, albeit controversially. In the present study, an in-vitro model was used to investigate the aortic valve hemodynamics of root remodeling and valve reimplantation; roots with supracommissural aortic replacement served as controls. METHODS: Aortic roots with aortoventricular diameter 21 mm were obtained from pigs. Root remodeling was performed using a 22-mm graft (group I, n = 6), or valve reimplantation with a 24-mm graft (group II, n = 7). Control roots were treated by supracommissural aortic replacement (22-mm graft; group III, n = 7). Using an electrohydraulic, computer-controlled pulse duplicator, the valves were tested at flows of 2, 4, 5, 7, and 9 I/min at a heart rate of 70 /min and a mean arterial pressure of 100 mmHg. Parameters assessed included: mean pressure gradient, effective orifice area, valve closure and regurgitant volume, and energy loss due to ejection, valve closure and regurgitation. Data were compared using ANOVA. RESULTS: There were no differences between the three groups in terms of regurgitant volume, energy loss due to valve regurgitation, or valve closure. The aortic valve orifice area was largest and systolic gradient lowest in group I at all flow rates (p < 0.001). Ejection energy loss was lowest in group I at all flow rates (9 l/min: group I, 128 +/- 21 mJ; group II, 399 +/- 46 mJ; group III, 312 +/- 27 mJ; p < 0.001). Valve closure volumes were similar in groups I and III, but significantly lower in group II at all flow rates (p = 0.047). CONCLUSION: In this standardized experimental setting, root remodeling--but not valve reimplantation--resulted in physiologic hemodynamic performance of the aortic valve with regard to orifice area, pressure gradient, and systolic energy loss.

Aortic valve repair using a differentiated surgical strategy.

BACKGROUND: Reconstruction of the aortic valve for aortic regurgitation (AR) remains challenging, in part because of not only cusp or root pathology but also a combination of both can be responsible for this valve dysfunction. We have systematically tailored the repair to the individual pathology of cusps and root. METHODS: Between October 1995 and August 2003, aortic valve repair was performed in 282 of 493 patients undergoing surgery for AR and concomitant disease. Root dilatation was corrected by subcommissural plication (n=59), supracommissural aortic replacement (n=27), root remodeling (n=175), or valve reimplantation within a graft (n=24). Cusp prolapse was corrected by plication of the free margin (n=157) or triangular resection (n =36), cusp defects were closed with a pericardial patch (n=16). Additional procedures were arch replacement (n=114), coronary artery bypass graft (n=60) or mitral repair (n=24). All patients were followed-up (follow-up 99.6% complete), and cumulative follow-up was 8425 patient-months (mean, 33+/-27 months).Results- Eleven patients died in hospital (3.9%). Nine patients underwent reoperation for recurrent AR (3.3%). Actuarial freedom from AR grade > or =II at 5 years was 81% for isolated valve repair, 84% for isolated root replacement, and 94% for combination of both; actuarial freedom from reoperation at 5 years was 93%, 95%, and 98%, respectively. No thromboembolic events occurred, and there was 1 episode of endocarditis 4.5 years postoperatively. CONCLUSIONS: Aortic valve repair is feasible even for complex mechanisms of AR with a systematic and individually tailored approach. Operative mortality is low and mid-term durability is encouraging. The incidence of valve-related morbidity is low compared with valve replacement.

Comparison of a silicon carbide-coated stent versus a noncoated stent in human beings: the Tenax versus Nir Stent Study's long-term outcome.

BACKGROUND: Stents coated with amorphous hypothrombogenic silicon carbide (a-SiC:H) have low restenosis rates in humans. Recurrence in a-SiC:H at mid-term follow-up has been shown to be similar to a stainless steel device. The long-term outcome, however, may be different. METHODS: Four hundred ninety-seven patients (63.4 +/- 9.8 years of age) received either the a-SiC:H-coated Tenax stent (Biotronik, Berlin, Germany) or the 316L Nir stent (Boston Scientific, Maple Grove, Minn). Lesions had to be covered with one stent only (diameter > or =2.8 mm, length <20 mm). Exclusion criteria comprised acute myocardial infarction and angiographic thrombus within the target vessel. Twenty-five of 497 (5%) patients were excluded for protocol violation. Clinical follow-up was completed in 450 of 472 (95.3%) and angiographic follow-up was completed in 365 of 472 (77.3%); 22 of 472 (4.7%) patients were lost to follow-up. RESULTS: Major adverse coronary events occurred in 28 of 233 (12%) of the Tenax recipients and in 31 of 217 (14.3%) of the Nir recipients (P =.50). Acute myocardial infarctions were less frequent in the Tenax recipients after > or =60 weeks. Premature target lesion revascularization was performed in 16 of 233 (6.9%) patients in the Tenax group and 11 of 217 (5.1%) (P =.54) patients in the Nir group. Coronary bypass operations were similar after Tenax or Nir stent deployment (3/233 [1.3%] vs 6/217 [2.8%], P =.43), as were deaths in 7 of 233 (3%) versus 8 of 217 (3.7%) (P =.88), respectively. CONCLUSIONS: Both stents had a low rate of major adverse coronary events at 81 +/- 12 weeks of follow-up, with no definite superiority of any of the devices.

Valve-sparing aortic root replacement in bicuspid aortic valves: a reasonable option?

OBJECTIVES: Aortic dilatation occurs in many patients with bicuspid aortic valves. We have added root replacement using the remodeling technique originally designed for tricuspid aortic valves to bicuspid aortic valve repair for treatment of the dilated root. We compared the results of remodeling in bicuspid aortic valves with those in tricuspid aortic valves. METHODS: From October 1995 through January 2004, 60 patients underwent root remodeling for bicuspid aortic valves (group A), and 130 patients underwent root remodeling for tricuspid aortic valves (group B). Correction of cusp prolapse was more often performed in group A (group A, 50/60; group B, 47/130; P < .0001). Transthoracic echocardiography was performed at 1 week, 6 and 12 months, and every year thereafter. Cumulative follow-up was 527 patient-years (mean, 2.9 +/- 2 years). RESULTS: No patient died in group A. Hospital mortality in group B was 5% (5/100; 95% confidence interval,1.6%-11.3%) after elective operations and 10% (3/30; 95% confidence interval, 2.1%-26.5%) after emergency operations. Mean systolic gradients were identical at 1 year (group A, 4.8 +/- 2.1 mm Hg; group B, 4.0 +/- 2 mm Hg) and 5 years (group A, 4.5 +/- 2.3 mm Hg; group B, 3.9 +/- 2.2 mm Hg). Freedom from aortic regurgitation of grade 2 or higher at 5 years was 96% in group A and 83% in group B ( P = .07), and freedom from reoperation at 5 years was 98% in group A and 98% in group B ( P = .73). CONCLUSIONS: Valve-sparing aortic replacement with root remodeling can be applied to aortic dilatation and a regurgitant bicuspid aortic valve. Hemodynamic function and valve stability of a repaired bicuspid aortic valve are comparable with those seen in cases of tricuspid anatomy.

Sleep-related breathing disorders are associated with ventricular arrhythmias in patients with an implantable cardioverter-defibrillator.

STUDY OBJECTIVES: The aim of this study was to examine the influence of sleep-related breathing disorders (SBDs) on the occurrence of ventricular arrhythmias in patients with reduced left ventricular ejection fraction (LVEF), and life-threatening ventricular tachyarrhythmias treated with an implantable cardioverter-defibrillator. PATIENTS: Thirty-eight patients with LVEF of 36 +/- 13% (mean +/- SD) underwent a sleep study. When an apnea-hypopnea index (AHI) > 10/h occurred, SBD was diagnosed. MEASUREMENTS AND RESULTS: In patients with SBDs, ventricular arrhythmias (couplets, triplets, short runs) were recorded simultaneously by Holter ECG and differentiated in episodes with and without disordered breathing. An apnea-associated arrhythmia index (AI) was defined as the number of ventricular arrhythmias occurring simultaneous to disordered breathing. Accordingly, a nonapnea-associated arrhythmia index (NAI) was calculated as the number of ventricular arrhythmias during normal breathing. SBDs were diagnosed in 14 patients: Cheyne-Stokes respiration (CSR) [n = 8; AHI, 32.1 +/- 25.0/h], and obstructive sleep apnea (OSA) [n = 6; AHI, 34.1 +/- 14.6/h]. Four patients in the OSA group and four patients in the CSR group had ventricular arrhythmias during sleep, revealed by Holter ECG. In these eight patients, the AI was significantly higher than the NAI (20.9 +/- 18.8/h vs 4.9 +/- 3.3/h, respectively). CONCLUSIONS: These data show that ventricular arrhythmias occurred significantly more often in association with disordered breathing in patients at high risk for arrhythmias and reduced LVEF.

Triggering effect of physical and mental stress on spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators.

BACKGROUND: Physical and mental stress as well as sexual activity are potential triggering factors of acute coronary events and sudden cardiac death. HYPOTHESIS: These factors may also trigger recurrence of spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators (ICDs). METHODS: We performed a case-crossover study in 43 consecutive patients with 95 symptomatic, ICD-documented tachyarrhythmic events and calculated the relative risk of tachyarrhythmia recurrence during physical and mental stress. Physical and mental activity was graded on a 4-step intensity scale, and stress was defined as physical exertion or mental stress with an intensity grade > or = II during or up to 1 h before arrhythmia recurrence. Relative risk was determined taking into account the habitual weekly stress frequency of each patient. RESULTS: Physical stress was present in 26% (n = 25), mental stress in 24% (n = 23), and sexual activity in 2% (n = 2) of analyzed events. The weekly habitual stress frequency was 8 +/- 8 (median 7) for physical stress, 6 +/- 6 (median 4) for mental stress, and 0.5 +/- 0.5 (median 0.25) for sexual activity. Thus, relative risk of arrhythmia recurrence during the presence of stress was 7.5 for physical activity (95% confidence interval [CI] 5.2-11.1), 9.5 (CI 6.3-14.5) for mental activity, and 7.5 (CI 2.3-24.8) for sexual activity. CONCLUSIONS: Physical and mental stress as well as sexual activity are factors that significantly increase relative risk of spontaneous recurrence of sustained ventricular tachyarrhythmias in patients with ICDs. Consideration of this stress-related relative risk increase may contribute to avoidance of harmful shock delivery in ICD recipients.

[Update cardiology 2001/2002-part II. From unstable coronary syndrome to terminal heart failure]. / Kardiologie 2001/2002-Teil II. Vom akuten Koronarsyndrom zur terminalen Herzinsuffizienz.

The cardiovascular continuum describes the way from risk factors to atherosclerosis, acute cardiovascular events (unstable angina and myocardial infarction), and development of terminal heart failure and its complications. Following this way, advances are reported in the therapy of acute coronary syndrome, heart failure, ventricular and supraventricular tachyarrhythmias, and stroke in patients with patent foramen ovale. The following issues are reported in detail: (1) significance of statins and statin withdrawal, glycoprotein IIb/IIIa receptor blocker, acute coronary interventions, aspirin and clopidogrel in unstable coronary syndromes, (2) pathogenesis of acute pulmonary edema associated with hypertension, (3) cardiac regeneration capability after transplantation and myocardial infarction, (4) beta-blocker therapy, efficacy of additional angiotensin receptor blocker therapy and multisite biventricular pacing in symptomatic (advanced) heart failure, (5) prognosis after ablation of the atrioventricular node in patients with atrial fibrillation, (6) primary prevention with an implantable defibrillator and resumption of driving after implantation, and (7) therapeutic options after cryptogenic stroke and patent foramen ovale.

[From risk factors to symptomatic coronary artery disease. Update cardiology 2001/2002--part I]. / Kardiologie 2001/2002--Teil I. Vom Risikofaktor zur symptomatischen koronaren Herzkrankheit.

The cardiovascular continuum describes the way from risk factors to atherosclerosis, acute cardiovascular events (unstable angina and myocardial infarction), and development of terminal heart failure and its complications. Following this way, advances are reported in the prevention of cardiovascular disease, in noninvasive diagnostics and revascularization of coronary artery disease, and in new therapeutic options of acute myocardial infarction. The following issues are reported in detail: (1) significance of statins, inhibition of platelet aggregation and vitamins in primary and secondary prevention of cardiovascular disease, (2) comparison of the angiotensin receptor blocker losartan and the beta-blocker atenolol in hypertension (LIFE study), (3) magnetic resonance angiography for the detection of coronary stenoses, (4) advantages and disadvantages of operative and interventional coronary revascularization considering elderly patients and sirolimus-eluting stents, and (5) efficacy of glycoprotein IIb/IIIa inhibition and low molecular weight heparin in acute myocardial infarction.

Aortic valve repair leads to a low incidence of valve-related complications.

OBJECTIVE: Aortic valve replacement for aortic regurgitation (AR) has been established as a standard treatment but implies prosthesis-related complications. Aortic valve repair is an alternative approach, but its mid- to long-term results still need to be defined. METHODS: Over a 12-year period, 640 patients underwent aortic valve repair for regurgitation of a unicuspid (n=21), bicuspid (n=205), tricuspid (n=411) or quadricuspid (n=3) aortic valve. The mechanism of regurgitation involved prolapse (n=469) or retraction (n=20) of the cusps, and dilatation of the root (n=323) or combined pathologies. Treatment consisted of cusp repair (n=529), root repair (n=323) or a combination of both (n=208). The patients were followed clinically and echocardiographically; follow-up was complete in 98.5% (cumulative follow-up: 3035 patient years). RESULTS: Hospital mortality was 3.4% in the total patient cohort and 0.8% for isolated aortic valve repair. The incidences of thrombo-embolism (0.2% per patient per year) and endocarditis (0.16%per patient per year) were low. Freedom from re-operation at 5 and 10 years was 88% and 81% in bicuspid and 97% and 93% in tricuspid aortic valves (p=0.0013). At re-operation, 13 out of 36 valves could be re-repaired. Freedom from valve replacement was 95% and 90% in bicuspid and 97% and 94% in tricuspid aortic valves (p=0.36). Freedom from all valve-related complications at 10 years was 88%. CONCLUSIONS: Reconstructive surgery of the aortic valve is feasible with low mortality in many individuals with aortic regurgitation. Freedom from valve-related complications after valve repair seems superior compared to available data on standard aortic valve replacement.

Aortic valve reconstruction in myxomatous degeneration of aortic valves: are fenestrations a risk factor for repair failure?

OBJECTIVE: Aortic valve repair is a more recent approach for the treatment of aortic regurgitation. Limited data exist for reconstruction in specific pathologies with isolated cusp pathology. We analyzed the results of aortic valve repair in patients with aortic regurgitation caused by myxomatous cusp prolapse in the presence of tricuspid valve anatomy and normal root size. METHODS: Over a 12-year period, 111 patients underwent aortic valve reconstruction for regurgitant tricuspid aortic valves without concomitant root dilatation. Cusp prolapse was caused by myxomatous degeneration in 72 subjects (group I) and associated with fenestrations in 39 subjects (group II). Prolapse was corrected by means of plication of the free margin in the presence of normal cusp tissue only (n = 62) or combined with triangular resection of cusp tissue (n = 10). It was treated with additional closure of the fenestration with autologous pericardium in 39 instances (group II). Follow-up was complete in 98.5% (cumulative 385 years). RESULTS: Hospital mortality was 1.8%, and during follow-up, there was 1 thromboembolic event and no endocarditis. Freedom from reoperation at 5 and 8 years was 96%. CONCLUSIONS: Isolated cusp prolapse is a relevant cause of aortic regurgitation in tricuspid aortic valves without concomitant root dilatation. In myxomatous stretching of cusp tissue, plication of the free margin suffices to restore cusp geometry and aortic valve function. In the presence of fenestrations, reconstruction of normal cusp configuration can be achieved by means of closure of the fenestration with a pericardial patch. The midterm stability of both approaches is good.

In vitro comparison of aortic valve movement after valve-preserving aortic replacement.

OBJECTIVE: In aortic valve regurgitation and aortic dilatation, preservation of the aortic valve is possible by means of root remodeling (Yacoub procedure) or valve reimplantation (David procedure). In vivo studies suggest that reimplantation might substantially influence aortic valve-motion characteristics. Evaluation of aortic valve movement in vivo, however, is technically limited and is difficult to standardize. We evaluated the aortic valve-motion pattern echocardiographically in vitro after reimplantation and remodeling. METHODS: By using aortic roots of house pigs (aortoventricular diameter, 22 mm) a Yacoub procedure (22-mm graft; group Y, n = 5) or a David I procedure (24-mm graft; group D, n = 5) was performed. Roots after supracommissural replacement (22-mm graft; group C, n = 5) served as control valves. In an electrohydraulic, computer-controlled pulse duplicator the valves were tested at flows of 2, 4, 7, and 9 L/min. Echocardiographically assessed parameters were rapid valve-opening velocity, slow valve-closing velocity, rapid valve-closing velocity, rapid valve-opening time, rapid valve-closing time, ejection time, maximum valve opening, slow valve-closing displacement, and maximum flow velocity. RESULTS: Mean rapid valve-opening velocity and mean rapid valve-closing velocity at a cardiac output of 2 to 9 L/min were fastest in group D (rapid valve-opening velocity: 69 +/- 10 cm/s [group D] vs 39 +/- 4 cm/s [group Y] vs 42 +/- 4 cm/s [group C], P = .0041; rapid valve-closing velocity: 22 +/- 2 cm/s [group D] vs 16 +/- 2 cm/s [group Y] vs 17 +/- 1 cm/s [group C], P = .0272), and slow valve-closing velocity was slowest in group D (0.2 +/- 0.1 cm/s [group D] vs 1.0 +/- 0.3 cm/s [group Y] vs 0.6 +/- 0.1 cm/s [group C], P = .0063). With increasing cardiac output, the difference in rapid valve-opening velocity between the groups increased, the difference in slow valve-closing velocity remained unchanged, and the difference in rapid valve-closing velocity decreased. CONCLUSIONS: In this standardized experimental setting remodeling of the aortic valve provides significantly smoother valve movements. This might contribute to preservation of a better valve performance during long-term follow-up.

Reversed circadian rhythms of heart rate variability and morning peak occurrence of sustained ventricular tachyarrhythmias in patients with implanted cardioverter defibrillator.

BACKGROUND: It is generally supposed that diurnal fluctuations of heart rate variability (HRV) are associated with diurnal variability of occurrence of sudden cardiac death, usually caused by tachyarrhythmias. To date, however, there have been no data comparing circadian rhythms of HRV and circadian variability of malignant ventricular tachyarrhythmias in the same patients. MATERIAL/METHODS: We studied 20 consecutive recipients of implantable cardioverter defibrillators in long-term follow-up, comparing the circadian rhythms of HRV in patients with and without typical morning peak occurrence of ventricular tachyarrhythmias. RESULTS: The HRV marker of vagus activity (RMSSD and HF power) displayed physiological circadian variability (highest values during sleep time, morning dip) only in patients without morning peak of arrhythmic events, and inverse circadian variability in patients with tachyarrhythmic morning peak. The variations in LF power and LF/HF ratio in both groups were not statistically significant, but with respect to the time interval between midnight and noon again showed inverse diurnal variation in patients with and without morning peak of arrhythmic events. CONCLUSIONS: These data suggest an association between a reversed circadian rhythm of HRV and morning peak frequency of tachyarrhythmic events in patients with ICD. As pronounced adrenergic hyperactivity in heart failure is the probable reason for paradoxically reversed circadian HRV variation, this association supports the hypothesis that the morning peak frequency of cardiovascular events may be interpreted as a sign of cardiovascular overload by the natural change from sleep to activity after awakening.

Comparison of a silicon carbide coated stent versus a noncoated stent in humans: the Tenax- versus Nir-Stent Study (TENISS).

PURPOSE: Stents coated with hypothrombogenic silicon carbide (a-SiC:H) exhibited low restenosis rates in the rabbit and in an observational study in humans. Thus, the clinical and angiographic outcome was assessed in a large multicenter study. MATERIAL AND METHODS: Four hundred and ninety-seven patients (63.4 +/- 9.8 years) were randomized to either receive the a-SiC:H-coated Tenax stent or the stainless steel Nir stent. Lesions (diameter > or = 2.8 mm, length < 20 mm) were covered with one single stent. RESULTS: Fifty-one of 497 (10.3%) patients were excluded for protocol violation. Three hundred and forty-two of 446 (76.7%) patients presented for scheduled angiographic follow-up after 4.7 +/- 1.2 months and 29 of 446 (6.5%) prematurely. In-hospital complications comprised two deaths (0.8%) (P > 0.99) and one (0.4%) (P > 0.99) CK-elevation in each group, target lesion revascularization in 5 of 250 (2%) of the Tenax and 4 of 244 (1.6%) of the Nir sample (P > 0.99), and subacute thrombosis in 2 of 250 (0.8%) of the Tenax patients (P = 0.5). In the Tenax/Nir patients mean percent diameter stenosis decreased from 82.3 +/- 9.1%/80.7 +/- 8.4% (P = 0.49) to 17.6 +/- 5.5%/17.6 +/- 5.5% (P = 0.99) postprocedure and increased to 34.5 +/- 21.5%/34.2 +/- 23.1% (P = 0.90) at follow-up. CONCLUSIONS: Thus, there appears to be no advantage of the silicon carbide coated stent over a stainless steel stent after 4.7 +/- 1.2 months with regard to clinical and angiographic restenosis rates.