Study (year)
NYHA class
Number of patients
Influence on HRQoL
MUSTIC (2001)
III
67
Significant improvement
PATH-CHF I (2002)
III-IV
42
Significant improvement
PATH-CHF II (2003)
II-IV
101
Significant improvement
MIRACLE (2002)
III-IV
453
Significant improvement
InSync ICD (2002)
II-IV
84
Significant improvement
MIRACLE ICD (2003)
III-IV
369
Significant improvement
CONTAK CD (2003)
II-IV
490
Trend towards improvement, lacking statistical significance; significant improvement only in subgroups of NYHA class III-IV patients
COMPANION (2004)
III-IV
1,520
Significant improvement
CARE-HF (2005)
III-IV
813
Significant improvement
The PATH-CHF I study also measured HRQoL using the MLHF questionnaire, with scores ranging from 0 points (best) to 105 points (worst). Prior to implantation of a biventricular pacemaker, patients rated their HRQoL to a mean value of 48.6 points. After implantation, this score dropped to 20 points (p < 0.001) [17]. Similar results were obtained in the PATH-CHF II study, which used the same questionnaire to measure QoL in a larger group of patients [18].
In contrast to the studies mentioned above, MIRACLE was the first randomized, prospective study with a double-blind sample involving a larger number of patients. This allowed for a wider measure of HRQoL in CHF patients with CRT, in which significant improvement was noted in QoL using the MLHF questionnaire (25).
The MLHF questionnaire was also used in the prospective InSync ICD study (26). Participants in NYHA classes II-IV had a low baseline HRQoL (mean, 53 points). CRT led to significant improvement in HRQoL after 1 month of treatment (mean, 31 points). This improvement was sustained after 3 (33 points), 6 (31 points), and 12 (31 points) months of observation. Similar to the studies mentioned above, simultaneous improvement was also noted in CHF symptoms.
MIRACLE ICD, a randomized, double-blind study, compared patients who received devices (i.e., with combined CRT and ICD capabilities) and controls (i.e., ICD activated, but CRT off). Similar to other studies, the MLHF questionnaire was used to measure QoL, and improvement was noted in both groups. However, compared with ICD patients, a significantly greater improvement in the MLHF questionnaire was noted in the CRT + ICD group at 6 months [21].
Only the CONTAK CD study did not find differences in the HRQoL of patients undergoing CRT alone versus CRT + ICD versus ICD alone. This study also used the MLHF questionnaire. Patients with symptomatic CHF (i.e., NYHA classes II-IV) were included in this study. After analyses, significant improvement in HRQoL was noted only in symptomatic CHF patients (i.e., NYHA classes III and IV) [22].
The most important trial was the COMPANION study [23]. This study encompassed 1,520 patients who were randomized into one of three groups: CRT, CRT + ICD, or pharmacotherapy alone. Using the MLHF questionnaire, significant improvement in HRQoL was noted in the groups undergoing CRT as opposed to pharmacotherapy alone. CRT improved the HRQoL of patients with significant left ventricular dysfunction and those with advanced CHF symptoms undergoing optimal pharmacotherapy. In the CARE-HF study, HRQoL measured by the MLHF questionnaire as well as EuroQoL-5D (EQ-5D) improved at 90 days [24].
The question is “which factors might be associated with improvement of HRQoL after CRT? Associations with age, sex, heart failure etiology, QRS width, and ejection fraction before CRT implantation were not found [27]. The only factor that predicted improvement after CRT was functional status (evaluated by NYHA classification). That is, patients with more symptoms of advanced heart failure at baseline responded better to CRT [28, 29].
Evidence that CRT does not “automatically” improve the subjective perception of being “healthier” came from randomized studies in which the device was switched off randomly in some patients whereas in others it remained switched on. After the observation period, an improvement in HRQoL was determined among the patients in whom CRT was switched on [30]. Kloch-Badelek et al. observed significant improvement in HRQoL after CRT implementation but only in a group of “responders” (defined as an increase in walking distance in the 6-minute Walk Test > 10% of baseline values). This finding may mean that patients with advanced heart failure perceive improvement in HRQoL after CRT if their physical ability improves [29].
Mechanical dyssynchrony may also have a role in the identification of subjects who may respond better to CRT. However, recent large clinical trials have challenged this concept. The role of CRT in heart-failure patients with narrow QRS (< 120 ms) is evolving. Such a group of patients was randomly assigned to CRT or optimal pharmacological treatment in the RESPOND study to evaluate clinical responses. HRQoL was assessed by the MLHF questionnaire. Six months after implantation, CRT led to an improvement in HRQoL scores and a reduction of NYHA class. However, no differences in total or cardiovascular mortality emerged between two groups [31].
CRT is mostly achieved by BVP, although it can also be provided by left ventricular pacing (LVP). However, the superiority of BVP over LVP remains uncertain. In 2011, Liang undertook a meta-analysis of randomized controlled trials to compare the effects of two modes of CRT in CHF patients. Outcomes included clinical status besides QoL. Five trials fulfilled the criteria for inclusion in the analysis, which involved 574 patients with CHF indicated for CRT. After a mid-term follow-up, pooled analyses demonstrated that LVP resulted in similar improvements in QoL, as well as other factors of clinical status (6-minute walk distance, NYHA class) [32].
7.5 ICD Therapy and HRQoL
A recognized form of ventricular arrhythmia therapy is implantation of an ICD. During the 1990s, several prospective, randomized studies broadened the indications for using ICD in the primary and secondary prevention of arrhythmia: the Antiarrhythmics Versus Implantable Defibrillators (AVID) [33]; the Canadian Implantable
Defibrillator Study (CIDS) [34]; the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) [35]; and the Multicenter Unsustained Tachycardia Trial (MUSTT) [36]. Studies focusing on the HRQoL of patients with an ICD found that they tolerated the device, but this acceptance was present only after a certain period of acclimatization to the device (≈6 months). During this period, the HRQoL of the patient (social, economic, and psychological aspects) was also lowest [37]. Unease and anxiety associated with the presence of the ICD device is often observed in patients. Should the device get discharged, increased uneasiness, anxiety, and fear of another discharge or death can be encountered. A subgroup of ICD patients experiences psychological difficulties, with the most profound manifestation being posttraumatic stress disorder [38]. Some patients may even remain in bed for extended periods of time [39]. Only one study did not find a difference in HRQoL between patients with an ICD device that discharged and patients without such an experience [40]. Compared with subjects with cardiovascular disease without an ICD device, most studies confirm a decreased HRQoL in patients after even one discharge [37, 39, 41], and this is influenced by several incidents of ICD discharge [42]. Schron et al. found that even one ICD discharge negatively affected psychological and physical health, whereas > 5 discharges significantly decreased HRQoL [43].
More recent studies have tried to identify predictors of risk of adverse psychological outcomes in subjects with an ICD. The evidence for an influence of ICD implantation and discharges on HRQoL is probably more complex than generally assumed. Symptomatic heart failure [44], younger age [45], poor social support [42], diabetes mellitus [46] and a type-D personality (patients who experience a range of negative emotions but who inhibit the expression of these emotions) [46] constitute other factors that have been associated with a risk of poorer HRQoL outcomes.
Sex has also been proposed to be a potentially important risk factor for poor HRQoL [47]. Sex disparities may be attributed to differences: in the way of dealing with stressful situations; in the acceptance of mechanical devices; in pain sensitivity [48]. Based on these findings, it would be rational to expect women to experience more psychological distress after ICD implantation than men. However, recent studies on sex differences in HRQoL have shown mixed findings. In a multicenter study with a 12-month follow-up of 718 patients, differences in HRQoL were observed for only 2 of 8 subscales of SF-36, with women reporting poorer physical functioning and vitality than men [49].
The Canadian Implantable Defibrillator Study (CIDS) found higher HRQoL in patients with an implanted ICD device compared with those receiving the antiarrhythmic drug amiodarone [50]. This study measured HRQoL in 317 patients using the Mental Health Inventory (MHI) and the Nottingham Health Profile (NHP). Self-rated physical and emotional health improved to a large degree in the ICD group, whereas self-rated emotional health remained unchanged and self-rated physical health worsened in the amiodarone group. However, after analyzing ICD patients who reported > 5 discharges in the previous 12 months, no advantages in terms of HRQoL were noted.
7.6 Conclusions
Improvement in the QoL is observed in most patients after implantation of cardiac devices. It refers mainly to subjects treated with singleor double-chamber pacemakers accompanied with a rate-response function and to CRT. Some studies showed that CRT can improve not only HRQoL, but also the prognosis in heartfailure patients. Conversely, those treated with an ICD device who experienced > 5 discharges may have a deterioration in HRQoL. Symptomatic heart failure, younger age, poor social support, diabetes mellitus, and a type-D personality are factors related to the risk of further decreases in HRQoL.
References
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Gribbin GM, Kenny RA, McCue P et al (2004) Individualised quality of life after pacing. Does mode matter? Europace 6:552–560PubMedCrossRef
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