Why do Myotonic Dystrophy Patients Die?

Myotonic Dystrophy patients have a shorter lifespan according to this study from 2016. A comprehensive review shows an average age of death at about 60 years. Lung issues and Heart Issues are the major casues of death. Sudden cardiac failure occurs in 27% of patients.

 

Causes and Predictors of Mortality in a Large U.S. Myotonic Dystrophy Type 1 Adult Cohort (P5.077)

Julian DudaYedatore VenkateshWilliam Groh
 
 

Abstract

Background: There is limited data on the causes and predictors of mortality in patients (pts) with myotonic dystrophy type 1 (DM1) evaluated and treated with modern medical therapy in the U.S. Objective: To determine the epidemiology of mortality in U.S. patients with DM1. Methods: Analysis from a U.S. registry with clinically- and genetically-verified adult DM1 pts (age at entry≥18 yrs) enrolled at MDA clinics (1997-2005) and prospectively followed (study entry-N=406; age: 42±12 yrs; male: 205 (50.5[percnt]); CTG repeats: 629±386; muscular impairment rating score (MIRS): 3.2±1.0). Causes of death were adjudicated by death certificate and medical records review. Results: By last follow-up (11.2±4.2 yrs), 170 (41.9[percnt]) of pts had died with a median age at death of 55.4 yrs. Causes of death in the 170 pts were respiratory failure (90, 52.9[percnt]), sudden unexpected possibly cardiac (47, 27.6[percnt]), non-sudden cardiac (8, 4.7[percnt]), non-sudden other (21, 12.4[percnt]), and uncertain cause (4, 2.4[percnt]). The median survival age was 60.5 yrs. Study entry characteristics predicting all-cause mortality using survival analysis included age (per decile, RR 1.5; 95[percnt] CI 1.3-1.7, p<0.001), MIRS (per 1-level increase, RR 1.7; 95[percnt] CI 1.5-2.1, p<0.001), CTG repeat length (per1-log increase, RR 1.9; 95[percnt] CI 1.2-3.0, p=0.006), cardiac diagnoses (if present, RR 2.7; 95[percnt] CI 2.0-3.7, p<0.001), and an abnormal EKG (if present, RR 2.4; 95[percnt] CI 1.7-3.3, p<0.001). Conclusions: Despite modern therapy, adult DM1 pts in the U.S. have a shortened lifespan. The most common causes of death are respiratory failure followed by cardiac causes. Predictors of death include older age, worsened muscular disability, greater CTG repeat length, and presence of cardiac issues either a diagnoses or abnormal EKG. Study Supported by: Research grant with Biogen, Inc. and Isis pharmaceuticals

Disclosure: Dr. Duda has nothing to disclose. Dr. Venkatesh has nothing to disclose. Dr. Groh has received personal compensation for activities with Isis Pharmaceuticals.

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Review Article on Myotonic Dystrophy

A new article was published on myotonic dystrophy from a number of researchers in Spain. This was a broad review by many specialists. We do not yet have a full review of the article but when the full article is available we will review it more thoroughly. Here are a few key conclusions:

The genetic diagnosis of myotonic dystrophy should quantify the number of CTG repetitions. -reason this gives some idea of the severity of the disease

Myotonic Dystrophy patients need cardiac and respiratory lifetime follow-up. These symtoms get worse with time and must be tracked

Before any surgery under general anaesthesia, a respiratory evaluation must be done for myotonic dystrophy patients. surgery is serious and the anesthesiologist needs to know the strength of the respiratory system.

Dysphagia in myotonic dystrophy must be screened periodically. – This can cause severe problems and can give an idea of the progression fo the disease

Genetic counselling must be offered to patients and relatives with myotonic dystrophy.

Here is the abstract from pubmed

Neurologia. 2019 Apr 16. pii: S0213-4853(19)30019-2. doi: 10.1016/j.nrl.2019.01.001. [Epub ahead of print]

Clinical guide for the diagnosis and follow-up of myotonic dystrophy type 1, MD1 or Steinert’s disease.

[Article in English, Spanish]Gutiérrez Gutiérrez G1Díaz-Manera J2Almendrote M3Azriel S4Eulalio Bárcena J5Cabezudo García P6Camacho Salas A7Casanova Rodríguez C8Cobo AM9Díaz Guardiola P4Fernández-Torrón R10Gallano Petit MP11García Pavía P12Gómez Gallego M13Gutiérrez Martínez AJ14Jericó I15Kapetanovic García S16López de Munaín Arregui A17Martorell L18Morís de la Tassa G19Moreno Zabaleta R20Muñoz-Blanco JL21Olivar Roldán J4Pascual Pascual SI21Peinado Peinado R22Pérez H23Poza Aldea JJ10Rabasa M24Ramos A3Rosado Bartolomé A25Rubio Pérez MÁ26Urtizberea JA9Zapata-Wainberg G27Gutiérrez-Rivas E28.

Author information

Abstract

BACKGROUND AND OBJECTIVES:

Steinert’s disease or myotonic dystrophy type 1 (MD1), (OMIM 160900), is the most prevalent myopathy in adults. It is a multisystemic disorder with dysfunction of virtually all organs and tissues and a great phenotypical variability, which implies that it has to be addressed by different specialities with experience in the disease. The knowledge of the disease and its management has changed dramatically in recent years. This guide tries to establish recommendations for the diagnosis, prognosis, follow-up and treatment of the complications of MD1.

MATERIAL AND METHODS:

Consensus guide developed through a multidisciplinary approach with a systematic literature review. Neurologists, pulmonologists, cardiologists, endocrinologists, neuropaediatricians and geneticists have participated in the guide.

RECOMMENDATIONS:

The genetic diagnosis should quantify the number of CTG repetitions. MD1 patients need cardiac and respiratory lifetime follow-up. Before any surgery under general anaesthesia, a respiratory evaluation must be done. Dysphagia must be screened periodically. Genetic counselling must be offered to patients and relatives.

CONCLUSION:

MD1 is a multisystemic disease that requires specialised multidisciplinary follow-up.

Copyright © 2018 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

KEYWORDS:

Clinical guideline; Complicaciones; Complications; Disfagia; Distrofia miotónica tipo 1; Dysphagia; Enfermedad de Steinert; Guía clínica; Myotonic dystrophy type 1; Recomendaciones; Recommendations; Steinert’s disease

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Long Term Outlook Longevity

LONG TERM OUTLOOK LONGEVITY FOR PATIENTS

Myotonic Dystrophy is a slowly progressive neuromuscular Disease and the symptoms of the disease do gradually get worse over time. However, there are a number of ways to manage the symptoms of the disease and more and more management techniques are becoming available. In the very long-term outlook most people with DM will have shorter life expectancies, One study available at the end of this post gives an average of 59 years for females with DM1 and 60 Years for males

For children with the Congenital form once  beyond the early problems of respiratory distress the prognosis for life is relatively good. There will be improvement in early childhood and children will make steady progress in these early years. Motor function will improve, most children will walk and the marked hypotonia or floppiness will improve or disappear. For most children their performance will be limited by mental capacity and not by physical handicap.

Reardon reports on the outcomes of 115 patients with confirmed diagnosis’s of CMD.   The data suggests a 25% of death before 18 months of age and a 50% chance of survival into the mid-30’s. tables that follow are from Reardon. The Natural History of Congenital myotonic Dystrophy: Mortality and long term aspects. Archives of Disease in Childhood 1993; 68:177-181

               Long-term Survival Probability

Age X

Probability of Survival to Age X

Age X

Probability of Survival to Age X

0

1.000

Days

1

.922

2

.887

3

.878

7

.861

10

.861

12

.843

20

.835

21

.826

Months

1

.807

234 .671

2

.791

240 .657

3

.791

249 .643

4

0774

274 .625

7

.765

304 .598

12

.765

315 .564

14

.757

388 .508

16

.745

462 .339

88

.737

474 .169

186

.724

486 (40 yr.) 0

195

.711

222

.698

223

.685

There was no instance of a congenitally affected patient having children. 48 patients reached the age of 20, 12 reached the age of 30. (of 115 patients). However, Reardon noted that “The degree of precision of estimated survival probabilities at the far end of the life table is recognized to be extremely poor” (or to put is more clearly he’s not sure how good the estimates are in the older years 30-40’s)During the study only 3 such individuals were studied and all died in this age band.

Details of Current Employment among the 48 patients reaching 20 years of Age

Employment No of Patients
Local Government Clerical Worker 1
Cinema Attendant 1
Garden Center Operative 1
Adult Training Workshop 5
Housewife 2
Unemployed 38

Most of the patients with CMD will be unemployed.

Chronic Medical Problems in surveying Patients n=71

Problem Number of Patients Percentage
Constipation/Diarrhea 24 34%
Recurrent Otitis 15 21%
Scoliosis 7 10%
Cardiac Rhythm Disturbance 3 4%
Vesicoureteric Reflux 1 1%

Causes of Death n=44

Cause No of Deaths
Constipation/Diarrhea 34%
Recurrent Otitis 21%
Scoliosis 10%
Cardiac Rhythm Disturbance 4%
Vesicoureteric Reflux 1%

However, during late childhood and early adolescence the “adult” features of myotonic dystrophy appear. Eye problems can be early on detected by the second decade and progressively muscles will be detected gradually weakening. No case of CMD has been found not to develop the adult version. O’Brien reports that of 46 patients with CMD 4 died outside the neonatal period at 4, 18, 19 and 22 years. Four more were considered seriously disabled with a poor prognosis. Problems seen in this group of 30 were gastrointestinal Problems in 8 (Constipation and abdominal pain) Talipes in 5. None in the group had any children and males showed marked testicular tubular failure indicating significant reproductive problems. Thus, long-term prognosis from a medical viewpoint is not bright.

Reardon noted that because of gastrointestinal problems children with CMD will show a positive anal dilation test. This test is sometimes used to diagnosis sexual abuse. Parents with CMD should be aware of this information. This test should not be used for any conclusive evidence of sexual abuse with children with CMD.

However, children with CMD are generally happy and cheerful individuals with a distinct personality and add a lot to family life as a whole. Medical outlook should be integrated with other family factors (see personal stories)

New Study May 1999:

A 10-year study of mortality in a cohort of patients with myotonic dystrophy.

Mathieu J; Allard P; Potvin L; Pr´evost C; B´egin P

Neuromuscular Clinic, Complexe Hospitalier de la Sagamie, Quebec University in Chicoutimi, Canada.

Neurology, 52(8):1658-62 1999 May 12

Abstract

OBJECTIVE: To determine the age and causes of death as well as the predictors of survival in patients with myotonic dystrophy (DM). METHODS: In a longitudinal study, a cohort of 367 patients with definite DM was followed for 10 years. RESULTS: During the 10-year period, 75 of the 367 DM patients (20%) died. The mean age at death (53.2 years, range 24 to 81) was similar for men and women. Among these 75 patients, 32 (43%) died of a respiratory problem, 15 (20%) of cardiovascular disease, 8 (11%) of a neoplasia, and 8 (11%) died suddenly. The ratio of observed to expected deaths was significantly increased to 56.6 (95% confidence interval [CI] 38.7 to 78.0) for respiratory diseases, 4.9 (95% CI 2.7 to 7.7) for cardiovascular diseases, and 2.5 (95% CI 1.1 to 4.6) for neoplasms. The mean age at death was 44.7 years for the childhood phenotype of DM, 47.8 years for the early-adult, 55.4 years for the adult, and 63.5 years for the mild phenotype (F = 4.8, p = 0.005). The age-adjusted risk of dying was 3.9 (95% CI 1.3 to 11.0) times greater for a patient with a distal weakness and 5.6 (95% CI 2.2 to 14.4) times greater for a patient with proximal weakness as compared with a person without limb weakness. CONCLUSIONS: Life expectancy is greatly reduced in DM patients, particularly in those with early onset of the disease and proximal muscular involvement. The high mortality reflects an increase in death rates from respiratory diseases, cardiovascular diseases, neoplasms, and sudden deaths presumably from cardiac arrhythmias.

Full text of Article above

Here is another study abstract on Longevity:

Age and causes of death in adult-onset myotonic dystrophy.

Author

de Die-Smulders CE; H¨oweler CJ; Thijs C; Mirandolle JF; Anten HB; Smeets HJ; Chandler KE; Geraedts JP

Address

Department of Clinical Genetics, Academic Hospital Maastricht, The Netherlands. christine.dedie@gen.unimaas.nl

Source

Brain, 121 ( Pt 8)():1557-63 1998 Aug

Abstract

Myotonic dystrophy is a relatively common type of muscular dystrophy, associated with a variety of systemic complications. Long term follow-up is difficult because of the slow progression. The objective of this study was to determine survival, age at death and causes of death in patients with the adult-onset type of myotonic dystrophy. A register of myotonic dystrophy patients was set up in Southern Limburg (the Netherlands), using data longitudinally collected over a 47-year period (1950-97). Survival for 180 patients (from the register) with adult-onset type myotonic dystrophy was established by the Kaplan-Meier method. The median survival was 60 years for males and 59 years for females. Survival of the patients was also estimated from the age of 15 years to the ages of 25, 45 and 65 years and compared with the expected survival of age- and sex-matched birth cohorts from the normal Dutch population. The observed survival to the ages of 25, 45 and 65 years was 99%, 88% and 18% compared with an expected survival of 99%, 95% and 78%, respectively. Thus, survival to the age of 65 in patients with adult-onset myotonic dystrophy is markedly reduced. A weak positive correlation between the CTG repeat length and younger age at death was found in the 13 patients studied (r = 0.50, P = 0.08). The cause of death could be determined in 70 of the 83 deceased patients. Pneumonia and cardiac arrhythmias were the most frequent primary causes of death, each occurring in approximately 30%, which was far more than expected for the general Dutch population. In addition, we assessed mobility in the years before death in a subgroup of 18 patients, as a reflection of the long-term physical handicap in myotonic dystrophy patients. Half of the patients studied were either partially or totally wheelchair-bound shortly before their death.

More information is available on the lifespan on the congenital form of myotonic dystrophy from a study in 1993. Medical care has improved since then.

Chart for Life span Congential Myotonic dystrophy
Mortality-and-long-term-clinical-outlook-congential-myotonic-dystrophy

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