OCT or Angiography Guidance for PCI in Complex Bifurcation Lesions

BACKGROUND

Imaging-guided percutaneous coronary intervention (PCI) is associated with better clinical outcomes than angiography-guided PCI. Whether routine optical coherence tomography (OCT) guidance in PCI of lesions involving coronary-artery branch points (bifurcations) improves clinical outcomes as compared with angiographic guidance is uncertain.

METHODS

We conducted a multicenter, randomized, open-label trial at 38 centers in Europe. Patients with a clinical indication for PCI and a complex bifurcation lesion identified by means of coronary angiography were randomly assigned in a 1:1 ratio to OCT-guided PCI or angiography-guided PCI. The primary end point was a composite of major adverse cardiac events (MACE), defined as death from a cardiac cause, target-lesion myocardial infarction, or ischemia-driven target-lesion revascularization at a median follow-up of 2 years.

RESULTS

We assigned 1201 patients to OCT-guided PCI (600 patients) or angiography-guided PCI (601 patients). A total of 111 patients (18.5%) in the OCT-guided PCI group and 116 (19.3%) in the angiography-guided PCI group had a bifurcation lesion involving the left main coronary artery. At 2 years, a primary end-point event had occurred in 59 patients (10.1%) in the OCT-guided PCI group and in 83 patients (14.1%) in the angiography-guided PCI group (hazard ratio, 0.70; 95% confidence interval, 0.50 to 0.98; P = 0.035). Procedure-related complications occurred in 41 patients (6.8%) in the OCT-guided PCI group and 34 patients (5.7%) in the angiography-guided PCI group.

CONCLUSIONS

Among patients with complex coronary-artery bifurcation lesions, OCT-guided PCI was associated with a lower incidence of MACE at 2 years than angiography-guided PCI. (Funded by Abbott Vascular and others; OCTOBER ClinicalTrials.gov number, NCT03171311.).

International randomized trial on the effect of revascularization or optimal medical therapy of chronic total coronary occlusions with myocardial ischemia - ISCHEMIA-CTO trial - rationale and design

BACKGROUND

Chronic total occlusions (CTO) are frequent among patients with coronary artery disease. Revascularization with percutaneous coronary intervention (PCI) is safe and feasible in experienced hands. However, randomized data are needed to demonstrate symptomatic as well as prognostic effect of CTO-PCI compared to optimal medical therapy alone.

METHODS

This trial aims to evaluate the effect of CTO PCI in patients with a CTO lesion and target vessel diameter ≥ 2.5 mm, and myocardial ischemia in the relevant territory. First, all patients are subjected to optimal medical therapy (OMT) for at least for 3 months and non-CTO lesions are managed according to guidelines. Subsequently, prior to randomization myocardial ischemia and quality of life (Seattle Questionnaire (SAQ)) is assessed. Patients are divided into two cohorts based on their SAQ score and randomized to either OMT alone or OMT and CTO-PCI. Cohort A is defined as Low- or asymptomatic patients with a quality-of-life score > 60 and/or CCS class < 2, and more than 10 % ischemia in the left ventricle (LV). Cohort B is symptomatic patients with a quality-of-life score < 60 or CCS class angina > 1 and at least ischemia in 5% of the LV. The primary end-point in cohort A is a composite of major adverse cardiac and cerebral events, hospitalization for heart failure and malignant ventricular arrhythmias. The primary endpoint in cohort B is difference in quality of life 6 months after randomization.

IMPLICATIONS

This trial is designed to investigate if CTO-PCI improves QoL and MACCE. Both positive and negative outcome of the trial will affect future guidelines and recommendations on how to treat patients with CTO.

Diagnostic Yield of Genetic Testing in Young Patients With Atrioventricular Block of Unknown Cause

Background

The cause of atrioventricular block (AVB) remains unknown in approximately half of young patients with the diagnosis. Although variants in several genes associated with cardiac conduction diseases have been identified, the contribution of genetic variants in younger patients with AVB is unknown.

Methods and Results

Using the Danish Pacemaker and Implantable Cardioverter Defibrillator (ICD) Registry, we identified all patients younger than 50 years receiving a pacemaker because of AVB in Denmark in the period from January 1, 1996 to December 31, 2015. From medical records, we identified patients with unknown cause of AVB at time of pacemaker implantation. These patients were invited to a genetic screening using a panel of 102 genes associated with inherited cardiac diseases. We identified 471 living patients with AVB of unknown cause, of whom 226 (48%) accepted participation. Median age at the time of pacemaker implantation was 39 years (interquartile range, 32–45 years), and 123 (54%) were men. We found pathogenic or likely pathogenic variants in genes associated with or possibly associated with AVB in 12 patients (5%). Most variants were found in the LMNA gene (n=5). LMNA variant carriers all had a family history of either AVB and/or sudden cardiac death.

Conclusions

In young patients with AVB of unknown cause, we found a possible genetic cause in 1 out of 20 participating patients. Variants in the LMNA gene were most common and associated with a family history of AVB and/or sudden cardiac death, suggesting that genetic testing should be a part of the diagnostic workup in these patients to stratify risk and screen family members.

Case report: spontaneous coronary artery dissection and suspicion of takotsubo cardiomyopathy in a patient presenting with T-wave inversions, severe QTc prolongation, elevated cardiac biomarkers, and apical akinesia

Background

In patients suspected of acute coronary syndrome, but where the coronary angiography (CAG) has shown unobstructed coronary arteries differential diagnoses include spontaneous coronary artery dissection and takotsubo cardiomyopathy. This case report presents a patient with spontaneous coronary artery dissection but diagnostic signs suspicious of takotsubo cardiomyopathy. Which leads to a consideration of the co-existence of the diseases.

Case summary

A 57-year-old woman was acutely admitted to the emergency ward with sudden development of chest discomfort, palpitations, and dyspnoea. At hospitalization, the electrocardiography showed T-wave inversions in I, aVL, and V2, and Troponin I was elevated. Initial echocardiography revealed apical akinesia consistent with takotsubo cardiomyopathy. Initially, a diagnosis of acute coronary syndrome or takotsubo cardiomyopathy was suspected. The patient was further diagnostically assessed with CAG including optical coherence tomography which showed spontaneous coronary artery dissection in the left anterior descending artery. At follow-up 3 months later, CAG showed a fully healed coronary artery, and repeated echocardiography showed normalization of the left ventricular function.

Discussion

In this case report, initially, acute coronary syndrome was suspected due to electrocardiography with T-wave inversions and elevated cardiac biomarkers. Takotsubo cardiomyopathy was suspected when echocardiography showed apical ballooning, but CAG with optical coherence tomography revealed a spontaneous coronary artery dissection. Interestingly no severe obstructions of coronary arteries were seen, and follow-up echocardiography showed fully regained myocardial function. This leads to the debate as to whether this might be a case of co-existing spontaneous coronary artery dissection and takotsubo cardiomyopathy.

Evolutionary dissection of mtDNA hg H: a susceptibility factor for hypertrophic cardiomyopathy

Mitochondrial DNA (mtDNA) haplogroup (hg) H has been reported as a susceptibility factor for hypertrophic cardiomyopathy (HCM). This was established in genetic association studies, however, the SNP or SNP's that are associated with the increased risk have not been identified. Hg H is the most frequent European mtDNA hg with greater than 80 subhaplogroups (subhgs) each defined by specific SNPs. We tested the hypothesis that the distribution of H subhgs might differ between HCM patients and controls. The subhg H distribution in 55 HCM index cases was compared to that of two Danish mtDNA hg H control groups (n = 170 and n = 908, respectively). In the HCM group, H and 12 different H subhgs were found. All these, except subhgs H73, were also found in both control groups. The HCM group was also characterized by a higher proportion of H3 compared to H2. In the HCM group the H3/H2 proportion was 1.7, whereas it was 0.45 and 0.54 in the control groups. This tendency was replicated in an independent group of Hg H HCM index cases (n = 39) from Queensland, Australia, where the H3/H2 ratio was 1.5. In conclusion, the H subhgs distribution differs between HCM cases and controls, but the difference is subtle, and the understanding of the pathogenic significance is hampered by the lack of functional studies on the subhgs of H.

Denmark: coronary and structural heart interventions from 2010 to 2015

Interventional cardiology in Denmark has been carried out since the mid 1980s. Interventional cardiology is only performed at a few high-volume centres. Healthcare coverage is universal and is essentially free of charge. Hospitals are mostly publicly owned and financed by fixed budgets and, in part, an activity-based funding system. Approximately 30,000 coronary angiographies (CAG), 10,000 percutaneous coronary interventions (PCIs) of which approximately 25% are primary PCIs, and 500 transcatheter aortic valve implantations (TAVIs) are carried out each year. The numbers of CAG and PCI have reached a plateau in recent years, whereas structural heart interventions, in particular TAVI, are increasing. Around 90% of all patients treated with PCI have a stent implanted, with more than 95% of these being drug-eluting stents. There is a low but increasing use of bioabsorbable scaffolds and drug-eluting balloons.

Functional effects of losartan in hypertrophic cardiomyopathy-a randomised clinical trial

OBJECTIVE

There is a lack of disease-modifying treatments in hypertrophic cardiomyopathy (HCM). The aim of this randomised, placebo-controlled study was to assess if losartan could improve or ameliorate deterioration of cardiac function and exercise capacity.

METHODS

Echocardiography, exercise test and MRI or CT were performed at baseline and after 12 months in 133 patients (52±13 years, 35% female) randomly allocated to losartan (100 mg/day) or placebo.

RESULTS

Losartan had no effect on systolic function compared with placebo (mean difference for left ventricular ejection fraction (LVEF) 0% (95% CI -3% to 4%), p=0.84 or global longitudinal strain 0.7% (95% CI -0.2% to 1.6%), p=0.13). Neither Doppler measures of diastolic function, left atrial volume (mean difference 2 mL/m(2) (95% CI -4 to 8 mL/m(2)) p=0.53) nor exercise capacity (mean difference -0.3 metabolic equivalents (METS) (95% CI -1.0 to 0.3 METS), p=0.28) differed between the treatment groups. At follow-up, there was further progression of disease, with the most prominent impairment being an increase in left atrial volume of 6 mL/m(2) (95% CI 3 to 9 mL/m(2), p<0.0001) in both groups combined. LVEF decreased (mean change -2%, (95% CI -3% to -1%), p=0.037) and 4% of patients had end-stage HCM with a LVEF of less than 50% at the end of the study.

CONCLUSION

Treatment with losartan had no effect on cardiac function or exercise capacity compared with placebo. Losartan fail to improve myocardial performance and failed to alter the progression of the disease. These findings do not support the use of angiotensin II receptor blockers as disease modifiers in adult patients with overt HCM.

TRIAL REGISTRATION NUMBER

NCT01447654-results.

Echocardiographic evaluation of pre-diagnostic development in young relatives genetically predisposed to hypertrophic cardiomyopathy

Identification of the first echocardiographic manifestations of hypertrophic cardiomyopathy may be important for clinical management and our understanding of the pathogenesis. We studied the development of pre-diagnostic echocardiographic changes in young relatives to HCM patients during long-term years follow-up. HCM-relatives not fulfilling the diagnostic criteria for HCM and age of <18 years were included in this study. We performed echocardiographic evaluations at inclusion and after 12 ± 1 years follow-up. Based on family screening of 11 sarcomere genes, CRYAB, α-GAL, and titin, we evaluated: (1) non-carriers (known family mutation ruled out-controls), (2) carriers (phenotype negative gene mutation carriers) and (3) phenotype negative relatives with unknown genetic status (relatives from families without identified mutations). At inclusion (age 11 ± 5 years), there were no differences in echocardiographic chamber dimensions, systolic or diastolic function between the three groups. During follow-up (age 23 ± 5 years), carriers (n = 8) developed lower left ventricular end-diastolic dimension (LVEDd) compared to non-carriers (n = 23) (41 ± 4 vs. 46 ± 4 mm; p = 0.04) and a higher ratio of early left ventricular filling velocity and early diastolic velocity of lateral mitral annulus (E/e' 6 ± 1 vs. 5 ± 1; p = 0.003). No significant differences in LVEDd or E/e' were found between relatives with unknown genetic status (n = 24) and non-carriers though Z-scores for these parameters were >2 in a subset of relatives with unknown genetic status. Children carrying pathogenic sarcomere gene mutations develop reduced LVEDd and increased E/e' as first pre-diagnostic echocardiographic manifestations during follow-up into adulthood.

Private mitochondrial DNA variants in danish patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease primarily caused by mutations in genes coding for sarcomeric proteins. A molecular-genetic etiology can be established in ~60% of cases. Evolutionarily conserved mitochondrial DNA (mtDNA) haplogroups are susceptibility factors for HCM. Several polymorphic mtDNA variants are associated with a variety of late-onset degenerative diseases and affect mitochondrial function. We examined the role of private, non-haplogroup associated, mitochondrial variants in the etiology of HCM. In 87 Danish HCM patients, full mtDNA sequencing revealed 446 variants. After elimination of 312 (69.9%) non-coding and synonymous variants, a further 109 (24.4%) with a global prevalence > 0.1%, three (0.7%) haplogroup associated and 19 (2.0%) variants with a low predicted in silico likelihood of pathogenicity, three variants: MT-TC: m.5772G>A, MT-TF: m.644A>G, and MT-CYB: m.15024G>A, p.C93Y remained. A detailed analysis of these variants indicated that none of them are likely to cause HCM. In conclusion, private mtDNA mutations are frequent, but they are rarely, if ever, associated with HCM.

Efficacy and safety of the angiotensin II receptor blocker losartan for hypertrophic cardiomyopathy: the INHERIT randomised, double-blind, placebo-controlled trial

BACKGROUND

No medical treatment has been reliably shown to halt or reverse disease progression in hypertrophic cardiomyopathy, but the results of several pilot studies have suggested beneficial effects of angiotensin II receptor blockers on left ventricular hypertrophy and fibrosis, which are predictive of an adverse outcome. We aimed to assess the effect of the angiotensin II receptor blocker losartan on left ventricular hypertrophy and fibrosis in patients with hypertrophic cardiomyopathy.

METHODS

In this single-centre, randomised, double-blind, placebo-controlled trial, adult patients (aged 18 years and older) with obstructive or non-obstructive hypertrophic cardiomyopathy were randomly assigned via computer-based system to losartan (100 mg per day) or placebo for 12 months. Patients and investigators were masked to assigned treatment. The primary endpoint was change in left ventricular mass as assessed by cardiac magnetic resonance imaging (CMR) or CT. Efficacy analyses were done in the modified intention-to-treat population (all patients with data available at the 12-month follow-up). The trial is registered with ClinicalTrials.gov, number NCT01447654.

FINDINGS

Between Dec 1, 2011, and May 1, 2013, 318 patients were screened. 133 patients (mean age 52 years [SD 13], 35% women) consented and were randomly assigned to placebo (n=69) or losartan (n=64). 124 (93%) patients completed the study and were included in the modified intention-to-treat analysis for the primary endpoint. After 12 months we noted no significant difference in the change in left ventricular mass between the placebo group and the losartan group (mean difference 1 g/m(2), 95% CI -3 to 6; p=0·60). A decrease in systolic blood pressure in the losartan group (from mean 127 mm Hg [SD 12] to 121 mm Hg [14]; p=0·0001) confirmed drug compliance; blood pressure did not decrease in the placebo group. Two (2%) patients, both in the placebo group, died from sudden cardiac death during follow-up. In the losartan group, one (1%) patient had angioedema, one (1%) had deterioration of renal function, and one (1%) had hyperkalaemia. Treatment was well tolerated by patients with left ventricular outflow obstruction at baseline.

INTERPRETATION

Our findings challenge the generally held view that angiotensin II receptor blockers reduce cardiac hypertrophy. Treatment with losartan was safe, suggesting that it can be used for other indications in patients with hypertrophic cardiomyopathy, irrespective of obstructive physiology. Additional studies are needed to assess the effect of angiotensin II receptor blockers in preclinical hypertrophic cardiomyopathy-eg, in genotype-positive but phenotype-negative individuals.

Stent thrombosis is the primary cause of ST-segment elevation myocardial infarction following coronary stent implantation: a five year follow-up of the SORT OUT II study

Background

The widespread use of coronary stents has exposed a growing population to the risk of stent thrombosis, but the importance in terms of risk of ST-segment elevation myocardial infarctions (STEMIs) remains unclear.

Methods

We studied five years follow-up data for 2,098 all-comer patients treated with coronary stents in the randomized SORT OUT II trial (mean age 63.6 yrs. 74.8% men). Patients who following stent implantation were readmitted with STEMI were included and each patient was categorized ranging from definite- to ruled-out stent thrombosis according to the Academic Research Consortium definitions. Multivariate logistic regression was performed on selected covariates to assess odds ratios (ORs) for definite stent thrombosis.

Results

85 patients (4.1%), mean age 62.7 years, 77.1% men, were admitted with a total of 96 STEMIs, of whom 60 (62.5%) had definite stent thrombosis. Notably, definite stent thrombosis was more frequent in female than male STEMI patients (81.8% vs. 56.8%, p = 0.09), and in very late STEMIs (p = 0.06). Female sex (OR 3.53 [1.01–12.59]) and clopidogrel (OR 4.43 [1.03–19.01]) was associated with increased for definite stent thrombosis, whereas age, time since stent implantation, use of statins, initial PCI urgency (STEMI [primary PCI], NSTEMI/unstable angina [subacute PCI] or stable angina [elective PCI]), and glucose-lowering agents did not seem to influence risk of stent thrombosis.

Conclusion

In a contemporary cohort of coronary stented patients, stent thrombosis was evident in more than 60% of subsequent STEMIs.

[The genome and cardiology]

Several cardiac diseases are autosomal dominantly inherited. This includes cardiomyopathies, primary arrhythmias (channelopathies), dyslipidaemias, premature ischaemic heart diseases and diseases of the thoracic aorta. Sudden cardiac death in the young is also often due to one of the inherited cardiac diseases. Clinical and genetic cascade family screening of the relatives to patients with inherited cardiac diseases is now organized in a national network of centres of cardiology, sharing pedigrees, clinical and genetic information. This gives unique opportunities for offering focused prophylaxis in the group of high-risk relatives.

Mitochondrial haplogroups modify the risk of developing hypertrophic cardiomyopathy in a Danish population

Hypertrophic cardiomyopathy (HCM) is a genetic disorder caused by mutations in genes coding for proteins involved in sarcomere function. The disease is associated with mitochondrial dysfunction. Evolutionarily developed variation in mitochondrial DNA (mtDNA), defining mtDNA haplogroups and haplogroup clusters, is associated with functional differences in mitochondrial function and susceptibility to various diseases, including ischemic cardiomyopathy. We hypothesized that mtDNA haplogroups, in particular H, J and K, might modify disease susceptibility to HCM. Mitochondrial DNA, isolated from blood, was sequenced and haplogroups identified in 91 probands with HCM. The association with HCM was ascertained using two Danish control populations. Haplogroup H was more prevalent in HCM patients, 60% versus 46% (p = 0.006) and 41% (p = 0.003), in the two control populations. Haplogroup J was less prevalent, 3% vs. 12.4% (p = 0.017) and 9.1%, (p = 0.06). Likewise, the UK haplogroup cluster was less prevalent in HCM, 11% vs. 22.1% (p = 0.02) and 22.8% (p = 0.04). These results indicate that haplogroup H constitutes a susceptibility factor and that haplogroup J and haplogroup cluster UK are protective factors in the development of HCM. Thus, constitutive differences in mitochondrial function may influence the occurrence and clinical presentation of HCM. This could explain some of the phenotypic variability in HCM. The fact that haplogroup H and J are also modifying factors in ischemic cardiomyopathy suggests that mtDNA haplotypes may be of significance in determining whether a physiological hypertrophy develops into myopathy. mtDNA haplotypes may have the potential of becoming significant biomarkers in cardiomyopathy.

MT-CYB mutations in hypertrophic cardiomyopathy

Mitochondrial dysfunction is a characteristic of heart failure. Mutations in mitochondrial DNA, particularly in MT-CYB coding for cytochrome B in complex III (CIII), have been associated with isolated hypertrophic cardiomyopathy (HCM). We hypothesized that MT-CYB mutations might play an important causal or modifying role in HCM. The MT-CYB gene was sequenced from DNA isolated from blood from 91 Danish HCM probands. Nonsynonymous variants were analyzed by bioinformatics, molecular modeling and simulation. Two germline-inherited, putative disease-causing, nonsynonymous variants: m.15024G>A; p.C93Y and m.15482T>C; p.S246P were identified. Modeling showed that the p.C93Y mutation leads to disruption of the tertiary structure of Cytb by helix displacement, interfering with protein–heme interaction. The p.S246P mutation induces a diproline structure, which alters local secondary structure and induces a kink in the protein backbone, interfering with macromolecular interactions. These molecular effects are compatible with a leaky phenotype, that is, limited but progressive mitochondrial dysfunction. In conclusion, we find that rare, putative leaky mtDNA variants in MT-CYB can be identified in a cohort of HCM patients. We propose that further patients with HCM should be examined for mutations in MT-CYB in order to clarify the role of these variants.

Penetrance of hypertrophic cardiomyopathy in children and adolescents: a 12-year follow-up study of clinical screening and predictive genetic testing

BACKGROUND

The penetrance of hypertrophic cardiomyopathy (HCM) during childhood and adolescence has been only sparsely described. We studied the penetrance of HCM and the short- and long-term outcomes of clinical screening and predictive genetic testing of child relatives of patients with HCM.

METHODS AND RESULTS

Ninety probands and 361 relatives were included in a family screening program for HCM (1994-2001). Eleven sarcomere genes, CRYAB, α-GAL, and titin were screened. Sixty-six relatives and 4 probands were <18 years of age at inclusion. Twelve child relatives were mutation carriers (age, 12 ± 5 years), and 26 had unknown genetic status, ie, relatives from families without identified mutations (n = 21) or not tested (n = 5) (age, 11 ± 5 years). Twenty-eight noncarriers (42%; age, 10 ± 4 years) served as control subjects. Two of 38 child relatives (5%) at risk of developing HCM fulfilled diagnostic criteria for HCM at inclusion. After 12 ± 1 years of follow-up, 2 of the 36 (6%; 95% confidence interval, 2-18) at-risk child relatives who were phenotype negative at inclusion had developed the HCM phenotype at 26 and 28 years of age. During follow-up, none of the child relatives experienced serious cardiac events. Participation in the screening program had no long-term negative psychological impact.

CONCLUSIONS

The penetrance of HCM in phenotype-negative child relatives at risk of developing HCM was 6% after 12 years of follow-up. The finding of phenotype conversion in the mid-20s warrants continued screening into adulthood. Forty-two percent of the child relatives were noncarriers, and repeat clinical follow-up could be safely limited to the remaining children.

Electrocardiographic features of sarcomere mutation carriers with and without clinically overt hypertrophic cardiomyopathy

In hypertrophic cardiomyopathy (HC), electrocardiographic (ECG) changes have been postulated to be an early marker of disease, detectable in sarcomere mutation carriers when left ventricular (LV) wall thickness is still normal. However, the ECG features of mutation carriers have not been fully characterized. Therefore, we systematically analyzed ECGs in a genotyped HC population to characterize ECG findings in mutation carriers (G+) with and without echocardiographic LV hypertrophy (LVH), and to evaluate the accuracy of ECG findings to differentiate at-risk mutation carriers from genetically unaffected relatives during family screening. The ECG and echocardiographic findings were analyzed from 213 genotyped subjects (76 G+/LVH-, 57 G+/LVH+ overt HC, 80 genetically unaffected controls). Cardiac magnetic resonance imaging was available on a subset. Q waves and repolarization abnormalities (QST) were highly specific (98% specificity) markers for LVH- mutation carriers, present in 25% of G+/LVH- subjects, and 3% of controls (p <0.001). QST ECG abnormalities remained independently predictive of carrying a sarcomere mutation after adjusting for age and impaired relaxation, another distinguishing feature of G+/LVH- subjects (odds ratio 8.4, p = 0.007). Myocardial scar or perfusion abnormalities were not detected on cardiac magnetic resonance imaging in G+/LVH- subjects, irrespective of the ECG features. In overt HC, 75% had Q waves and/or repolarization changes, but <25% demonstrated common isolated voltage criteria for LVH. In conclusion, Q waves and repolarization abnormalities are the most discriminating ECG features of sarcomere mutation carriers with and without LVH. However, owing to the limited sensitivity of ECG and echocardiographic screening, genetic testing is required to definitively identify at-risk family members.

Long-term outcome of percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: a Scandinavian multicenter study

BACKGROUND

Single-center reports on percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy have shown considerable differences in outcome.

METHODS AND RESULTS

We report the long-term outcome of 313 PTSMA procedures performed in 279 patients with hypertrophic obstructive cardiomyopathy aged 59±14 years from 1999 to 2010 in 4 Scandinavian centers. Sixty-nine percent of patients had ≥1 comorbidity at baseline. The median (interquartile range) of left ventricular outflow tract gradient at rest was reduced from 58 mm Hg (34 to 89 mm Hg) at baseline to 12 mm Hg (8 to 24 mm Hg) at 1-year (P<0.001) and during Valsalva maneuver from 93 mm Hg (70 to 140 mm Hg) to 21 mm Hg (11 to 42 mm Hg) (P<0.001). The proportion of patients with syncope was reduced from 18% to 2% (P<0.001), and the proportion in New York Heart Association class III/IV was reduced from 94% to 21% (P<0.001). All treatment effects remained stable during the follow-up. New York Heart Association class III/IV at the most recent follow-up (2.9±2.6 years) was associated with diabetes mellitus (P=0.03), chronic obstructive pulmonary disease (P=0.02), and valve disease unrelated to hypertrophic cardiomyopathy (P<0.01). In-hospital mortality was 0.3%. The 1-, 5- and 10-year survival rates were 97%, 87%, and 67%, respectively (P=0.06 versus an age- and sex-matched background population) in all patients and 99%, 94%, and 88%, respectively (P=0.12) in patients aged <60 years (48±9 years, n=141). Age (hazard ratio, 1.07; 95% CI, 1.03 to 1.1) was the only predictor of survival.

CONCLUSIONS

In this multicenter study, the in-hospital mortality after PTSMA was low despite considerable comorbidities. The hemodynamic and symptomatic effects were sustained long term. The long-term symptomatic outcome was associated with baseline comorbidities. The 10-year survival rate was comparable to that in an age- and sex-matched background population, and age was the only predictor of survival.

[Another genetic cause of sudden cardiac death]

Mutations in the Lamin A/C gene (LMNA) are a new part of the spectrum of genes responsible for sudden cardiac death (SCD). Relatives of SCD-cases should receive counselling, clinical assessment and perhaps molecular screening. The consequence of being an LMNA mutation carrier is discussed with regard to counselling and prophylactic measures. Device therapy may be relevant in LMNA-mutation carriers, although the proper time for implantation is uncertain. However, we recommend LMNA genetic screening in SCD cases with dilated cardiomyopathy as well as cases with unexplained SCD.

Echocardiographic strain imaging to assess early and late consequences of sarcomere mutations in hypertrophic cardiomyopathy

BACKGROUND

Genetic testing identifies sarcomere mutation carriers (G+) before clinical diagnosis of hypertrophic cardiomyopathy (HCM), allowing characterization of initial disease manifestations. Previous studies demonstrated that impaired relaxation develops before left ventricular hypertrophy (LVH). The precise impact of sarcomere mutations on systolic function in early and late disease is unclear.

METHODS AND RESULTS

Comprehensive echocardiography with strain imaging was performed on 146 genotyped individuals with mutations in 5 sarcomere genes. Contractile parameters were compared in 68 preclinical (G+/LVH-), 40 overt (G+/LVH+) subjects with HCM, and 38 mutation (-) normal control relatives. All subjects had normal left ventricular ejection fraction. In preclinical HCM, global and regional peak systolic strain (epsilon(sys)) and longitudinal systolic strain rate were not significantly different from controls, but early diastolic mitral annular velocity (Ea) was reduced by 13%. In overt HCM, there was a significant 27% and 14% decrease in global longitudinal epsilon(sys) and systolic strain rate, respectively, compared with both preclinical HCM and controls (P<0.013 for all comparisons), and a 33% reduction in Ea.

CONCLUSIONS

Sarcomere mutations have disparate initial effects on diastolic and systolic functions. Preclinical HCM is characterized by impaired relaxation but preserved systolic strain. In contrast, both diastolic and longitudinal systolic abnormalities are present in overt disease despite normal ejection fraction. We propose that diastolic dysfunction is an early consequence of sarcomere mutations, whereas systolic dysfunction results from mutations combined with subsequent pathological remodeling. Identifying mechanistic pathways triggered by these mutations may begin to reshape the clinical paradigm for treatment, based on early diagnosis and disease prevention.

Diagnostic yield, interpretation, and clinical utility of mutation screening of sarcomere encoding genes in Danish hypertrophic cardiomyopathy patients and relatives

The American Heart Association (AHA) recommends family screening for hypertrophic cardiomyopathy (HCM). We assessed the outcome of family screening combining clinical evaluation and screening for sarcomere gene mutations in a cohort of 90 Danish HCM patients and their close relatives, in all 451 persons. Index patients were screened for mutations in all coding regions of 10 sarcomere genes (MYH7, MYL3, MYBPC3, TNNI3, TNNT2, TPM1, ACTC, CSRP3, TCAP, and TNNC1) and five exons of TTN. Relatives were screened for presence of minor or major diagnostic criteria for HCM and tracking of DNA variants was performed. In total, 297 adult relatives (>18 years) (51.2%) fulfilled one or more criteria for HCM. A total of 38 HCM-causing mutations were detected in 32 index patients. Six patients carried two disease-associated mutations. Twenty-two mutations have only been identified in the present cohort. The genetic diagnostic yield was almost twice as high in familial HCM (53%) vs. HCM of sporadic or unclear inheritance (19%). The yield was highest in families with an additional history of HCM-related clinical events. In relatives, 29.9% of mutation carriers did not fulfil any clinical diagnostic criterion, and in 37.5% of relatives without a mutation, one or more criteria was fulfilled. A total of 60% of family members had no mutation and could be reassured and further follow-up ceased. Genetic diagnosis may be established in approximately 40% of families with the highest yield in familial HCM with clinical events. Mutation-screening was superior to clinical investigation in identification of individuals not at increased risk, where follow-up is redundant, but should be offered in all families with relatives at risk for developing HCM.

[Long QT syndrome--genes, mechanisms and risks. Indication for genetic family screening?]

Inherited long QT syndrome (LQTS) is a cardiac disease characterised by episodes of ventricular tachyarrhythmia, presenting as syncope or sudden death. Untreated, the annual mortality rate is 1-2%. Sudden death has been reported as the first manifestation of the disease in some cases. Therefore, early (pre-symptomatic) diagnosis and management may save lives. However, clinically false negative relatives are also at risk of sudden death. On this basis we conclude assessment of relatives should be extended with genetic testing.

Genetic and phenotypic characterization of mutations in myosin-binding protein C (MYBPC3) in 81 families with familial hypertrophic cardiomyopathy: total or partial haploinsufficiency

Mutations in the MYBPC3 gene, encoding the sarcomere protein myosin-binding protein C, are among the most frequent causes of autosomal dominant familial hypertrophic cardiomyopathy (FHC). We studied the frequency, type, and pathogenetic mechanism of MYBPC3 mutations in an unselected cohort of 81 FHC families, consecutively enrolled at a tertiary referral center. Nine mutations, six of which were novel, were found in 10 (12.3%) of the families using single-strand conformation polymorphism and DNA sequencing. A frameshift mutation in exon 2 clearly suggests that haploinsufficiency is a pathogenetic mechanism in FHC. In addition, splice site mutations in exon 6 and intron 31, a deletion in exon 13, and a nonsense mutation in exon 25, all lead to premature termination codons, most likely causing loss of function and haploinsufficiency. Furthermore, there were two missense mutations (D228N and A833 T) and one in-frame deletion (DeltaLys813). A considerable intrafamilial variation in phenotypic expression of MYBPC3-based FHC was noted, and we suggest that mutations influencing stability of mRNA could play a role in the variable penetrance and expressivity of the disease, perhaps via partial haploinsuffciency.

One third of Danish hypertrophic cardiomyopathy patients have mutations in MYH7 rod region

Familial hypertrophic cardiomyopathy (FHC) is, in most cases, a disease of the sarcomere, caused by a mutation in one of 10 known sarcomere disease genes. More than 266 mutations have been identified since 1989. The FHC disease gene first characterized MYH7, encodes the cardiac beta-myosin heavy chain, and contains more than 115 of these mutations. However, in most studies, only the region encoding the globular head and the hinge region of the mature cardiac beta-myosin heavy chain have been investigated. Furthermore, most studies carries out screening for mutations in the most prevalent disease genes, and discontinues screening when an apparent disease-associated mutation has been identified. The aim of the present study was to screen for mutations in the rod region of the MYH7 gene in all probands of the cohort, regardless of the known genetic status of the proband. Three disease-causing mutations were identified in the rod region in four probands using capillary electrophoresis single-strand conformation polymorphism as a screening method. All mutations were novel: N1327K, R1712W, and E1753K. Two of the probands had already been shown to carry other FHC-associated mutations. In conclusion, we show that in the Danish cohort we find one third of all MYH7 mutations in the rod-encoding region and we find that two of the patients carrying these mutations also carry mutations in other FHC disease genes stressing the need for a complete screening of all known disease genes in FHC-patients.

Outcome of clinical versus genetic family screening in hypertrophic cardiomyopathy with focus on cardiac beta-myosin gene mutations

OBJECTIVE

Familial hypertrophic cardiomyopathy (FHC) is caused by mutations in genes encoding cardiac sarcomere proteins. Although available, genetic analyses are generally not used clinically. In the present study, we evaluated the outcome of clinical vs. genetic screening of family members with specific focus on mutations in the cardiac beta-myosin heavy chain (MYH7) gene.

METHODS

A consecutive cohort of 68 FHC probands and their families (395 persons) of Danish origin was evaluated including patient- and family histories, physical examinations, electrocardiogram and echocardiography. Mutation screening was performed by a combination of single strand conformation/heteroduplex analysis and direct sequencing.

RESULTS

Eight different MYH7 gene mutations were identified in nine (13%) families (96 persons). In eight (89%) of the families, major cardiac events had occurred. Myectomy or percutaneous septal alcohol ablation had been performed in a higher number of MYH7 probands i.e. in five of nine (56%) as compared to 10 of 59 (17%) (P<0.05) non-MYH7 mutation probands. Neither echocardiographic nor ECG findings were useful to distinguish MYH7 from non-MYH7 probands. Between adult MYH7 mutation-carriers (n=38) and their non-carrier relatives (n=39), low sensitivity and specificity of the clinical diagnostic criteria tested were observed and minor clinical diagnostic criteria alone were not useful for identification of mutation carriers. By genetic screening of relatives with no or only minor hypertrophy on echocardiography, i.e. a priori possible mutation-carriers normally recommended clinical follow-up-the diagnosis was excluded in 52 (83%) persons. In addition, six relatives with secondary hypertrophy were identified as non-carriers.

CONCLUSION

Neither echocardiographic nor ECG findings were useful to distinguish MYH7 from non-MYH7 probands. Extension of screening to include genetic analyses offered a marked diagnostic advantage as compared to clinical screening alone in FHC families.

Predictors of coronary in-stent restenosis: importance of angiotensin-converting enzyme gene polymorphism and treatment with angiotensin-converting enzyme inhibitors

OBJECTIVES

This study aimed to clarify the role of the angiotensin-converting enzyme (ACE) gene polymorphism in the development of in-stent restenosis.

BACKGROUND

In-stent restenosis occurs after treatment of coronary artery stenosis in 12% to 32% of coronary interventions with stents. Experimental and clinical studies have suggested that the deletion/insertion (D/I) polymorphism of the ACE gene plays a role in this.

METHODS

Quantitative coronary angiography before, immediately after and six months after stent implantation were compared in 369 patients, in whom D/I typing of the ACE gene was performed.

RESULTS

At follow-up we found no differences between the three genotypes in minimal lumen diameter (homozygotes with two deletion alleles in the ACE gene [DD], 2.20 mm; heterozygotes with one deletion and one insertion allele in the ACE gene [DI], 2.19 mm; and homozygotes with two insertion alleles in the ACE gene [II], 2.25 mm). The corresponding diameter stenoses were: DD: 25%, DI: 27%, II: 27% (p = NS), and the frequency of restenosis (>50% diameter stenosis) was: DD: 15.7%, DI: 11.0% and II: 16.4% (p = NS). Logistic regression analysis identified diabetes (odds ratio [OR]: 3.0, 95% confidence interval [CI]: 1.0 to 8.7), lesion length (OR: 1.1, 95% CI: 1.01 to 1.30) and minimal lumen diameter immediately after the intervention (OR: 0.3, 95% CI: 0.14 to 0.85) as predictors of in-stent restenosis. In a post hoc analysis of patients treated versus those not treated with an ACE-inhibitor antagonist or an angiotensin receptor antagonist, we found an increased frequency of in-stent restenosis in the DD genotypes (40% vs. 12%, p = 0.006).

CONCLUSIONS

The D/I polymorphism is not an independent predictor of coronary in-stent restenosis in general, but it may be of clinical importance in patients treated with ACE inhibitors or angiotensin receptor antagonists.

Outcome of septal myectomy in patients with hypertrophic obstructive cardiomyopathy

OBJECTIVES

To study the outcome of septal myectomy in patients with hypertrophic obstructive cardiomyopathy.

DESIGN

Septal myectomy in patients with hypertrophic cardiomyopathy with obstruction of the left ventricular outflow tract (HOCM) is symptomatically effective, and complication rates have been found to be low in large centres performing the procedure routinely. Representing a small centre we studied the outcome after septal myectomy in 11 consecutive patients, aged 44 +/- 21 (mean +/- SD) years with HOCM myectomized at our institution from 1991 to 1998. The patients were evaluated preoperatively using echocardiography and left-sided heart catheterization.

RESULTS

Eight patients were operated on after medical treatment had failed and three after sudden deterioration of cardiac function. A Morrow myectomy was performed in 10 patients and a modified Konno procedure in one. Significant reductions were observed in left ventricular outflow tract gradients (77 +/- 29 to 10 +/- 7 mmHg, p < 0.01; n = 11), the degree of mitral valve regurgitation (grades 0-3) (1.7 +/- 1.0 to 0.8 +/- 0.7, p < 0.01; n = 11), NYHA functional classification score (2.4 +/- 1.0 to 1.5 +/- 0.7, p < 0.01; n = 11) and all five patients with angina preoperatively had an improved CCS angina classification score. There were no operative or early postoperative (30 days) deaths. One patient operated on with the modified Konno procedure was reoperated for a septal patch suture leak. During follow-up (43 +/- 24 months, range 11-83), the linearized mortality rate was 3.6% per year. One patient died from a pancreas cancer, one probably from coronary artery disease and one suddenly of unknown cause.

CONCLUSION

We conclude that septal myectomy efficiently relieves symptoms in HOCM patients, possibly reflecting the direct as well as secondary effects of left ventricular outflow tract gradient reduction. The present results, obtained at a smaller centre for this procedure, should be considered when choosing from available therapeutic alternatives when medical therapy fails: dual chamber pacemaker implantation, percutaneous transluminal septal myocardial ablation or myectomy.

A novel missense mutation, Leu390Val, in the cardiac beta-myosin heavy chain associated with pronounced septal hypertrophy in two families with hypertrophic cardiomyopathy

OBJECTIVE

An examination of the genetic background and phenotypic presentation of familial hypertrophic cardiomyopathy (FHC) with respect to specific mutations in the MYH7-gene encoding the cardiac beta-myosin heavy chain.

SETTINGS

Two families (n = 22) from a cohort of 67 families with FHC were studied at the National University Hospital, Rigshospitalet, Copenhagen.

METHODS

Clinical, non-invasive examinations of all included family members followed by molecular genetic analysis including PCR-single strand conformation polymorphism/heteroduplex (SSCP/HD) analysis and sequencing of exon 3-23 of the MYH7-gene.

RESULTS

We found FHC associated with a missense mutation in two families, i.e. a C > G transversion at position g10124 and a G > T transversion at position g10126 causing the change of a leucine residue at codon 390 to a valine residue. The mutation is located in the actin-binding region of the beta-myosin heavy chain. The leucine residue is evolutionarily conserved in vertebrate myosins. In the two families, the phenotypic presentations in the clinically affected were characterized by asymmetric septal hypertrophy (septum diameter 18.8 (5.0) mm (mean (SD)) with only minor involvement of the left ventricular free wall (posterior wall diameter 11.0 (2.2) mm). Furthermore, the left ventricular systolic and diastolic functions were well preserved, even at a high age. The symptomatic status of the clinically affected patients depended on the presence or absence of a concomitant left ventricular outflow tract gradient.

CONCLUSIONS

We report a novel missense mutation associated with FHC caused by a double nucleotide transversion. The penetrance of the mutation was not complete, but in clinically affected patients the mutation gives rise to an echocardiographic phenotype, predominantly characterized by pronounced septal hypertrophy.

Familial hypertrophic cardiomyopathy associated with a novel missense mutation affecting the ATP-binding region of the cardiac beta-myosin heavy chain

Mutations in the cardiac beta -myosin heavy chain gene (MYH7), and other genes encoding cardiac sarcomere proteins may cause familial hypertrophic cardiomyopathy (F-HCM), an autosomal dominant disease, characterized by myocardial hypertrophy. We analysed the MYH7 gene in three generations of a family with one borderline and four clinically verified cases of hypertrophic cardiomyopathy, and identified a mutation in exon 7 changing the 190 arginine residue into a threonine residue. The mutation is located in the ATP-binding region of the myosin head and alters the charge in the F-helix close to the phosphate-binding P-loop. The mutation may thus interfere with the coupling between ATP-hydrolysis and the transition into mechanical energy. In conclusion, the novel Arg190Thr mutation in exon 7 of the MYH7 gene is associated with the development of symptomatic myocardial hypertrophy in adults.

[Hypertrophic cardiomyopathy]

Hypertrophic cardiomyopathy is a heterogeneous, progressive disease with a variable age of debut. Hypertrophic cardiomyopathy is characterized by myocardial hypertrophy with a bizarre fibre disarray. Angina pectoris, dyspnoea and syncope are the most frequent symptoms. Hypertrophic cardiomyopathy is an important cause of sudden death, especially in children and young adults. The aetiology is genetic in more than 60% of the cases, with an autosomal dominant mode of inheritance. More than 50 different mutations involving six genes have so far been associated with the development of hypertrophic cardiomyopathy. These mutations are located to genes coding for several of the proteins in the cardiac sarcomere. The protein changes seem to compromise contractility as well as sarcomere assembly, thereby secondarily causing compensatory hypertrophy. The management of hypertrophic cardiomyopathy has been markedly improved within the last few years. This emphasizes the importance of determining prognostic markers in each patient. A specific genetic diagnosis may prove to be of major importance.

[Treatment of hypertrophic cardiomyopathy]

The medical management of hypertrophic cardiomyopathy is reviewed. Four cases of hypertrophic cardiomyopathy are presented, and serve to describe the currently available invasive treatment modalities, i.e. septal myectomy, dual chamber pacing, cardioverter defibrillator implantation and heart transplantation. These different invasive treatments all seem to be symptomatically effective in carefully selected patients, but studies of prognostic effects are not available. Finally, new experimental procedures are presented.