Results

Demographic data, co-morbidities and long-term survival was available in 4896 patients. Information on frailty at index hospitalization for M-TEER and long-term survival was available in 4631 individuals, respectively. The baseline characteristics are shown in Table 2.

 | All patients | No impairments | Level 1 | Level 2 | Level 3–5
Number of. pts., n (%) | 4896 (100) | 3665 (74.8) | 265 (5.4) | 679 (13.8) | 287 (5.8)
Age (Median, IQR) | 81 (77–84) | 81 (76–84) | 83 (79–86) | 82 (78–86) | 82 (77–86)
Male (%) | 2227 (45.5) | 1777 (48.5) | 81 (30.5) | 249 (36.7) | 120 (41.8)
Heart failure (%) | 4739 (96.7) | 3530 (96.3) | 260 (98.1) | 667 (98.2) | 282 (98.2)
Left heart failure (%) | 4624 (94.4) | 3433 (93.6) | 254 (95.8) | 658 (96.9) | 279 (97.2)
NYHA Class (Median, IQR) | 4 (3–4) | 3 (3–4) | 4 (3–4) | 4 (3–4) | 4 (3–4)
Right heart failure (%) | 2864 (58.5) | 2001 (54.6) | 174 (65.6) | 473 (69.6) | 216 (75.2)
Coronary artery disease (%) | 4263 (87.1) | 3170 (86.5) | 235 (88.7) | 604 (88.9) | 254 (88.5)
Previous coronary artery bypass grafting (%) | 790 (16.1) | 596 (16.3) | 41 (15.5) | 109 (16) | 44 (15.3)
Atrial fibrillation (%) | 3965 (80.9) | 2921 (79.7) | 227 (85.6) | 568 (83.6) | 249 (86.7)
Arterial hypertension (%) | 4744 (96.8) | 3530 (96.3) | 259 (97.7) | 672 (97.5) | 283 (98.6)
Peripheral artery disease | 1034 (21.1) | 698 (19) | 58 (21.8) | 181 (26.6) | 97 (33.8)
Chronic pulmonary artery disease (%) | 1451 (29.6) | 975 (26.6) | 102 (38.5) | 256 (37.7) | 118 (41.1)
Dementia (%) | 254 (5.1) | 139 (3.8) | 17 (6.4) | 50 (7.4) | 48 (16.7)
Diabetes Type I (%) | 257 (5.2) | 172 (4.7) | 17 (6.4) | 44 (6.5) | 24 (8.3)
Diabetes Type II (%) | 2029 (41.4) | 1438 (39.2) | 115 (43.4) | 326 (48.1) | 150 (52.3)
Chronic renal failure (%) | 3329 (67.9) | 2375 (64.8) | 188 (70.9) | 524 (77.1) | 242 (84.3)
Stage of chronic renal failure (Median, IQR) | 3 (3–4) | 3 (3–4) | 3 (3–4) | 3 (3–4) | 3 (3–4)

Age

Patients were split into three age groups (group 1: 50–69 years (young patients), group 2: 70–79 years (old patients), and group 3: 80–99 years (very old patients)), and long-term survival was analysed, [10] respectively. Group 1 comprised of 458 (9.4%) patients, group 2 of 1467 (29.9%) patients, and group 3 contained the largest patient sample with 2971 (60.7%) individuals. During a four-year period, 2122 (43.3%) of 4896 patients died. As compared to young patients, very old patients had a decreased survival rate (OR 1.3, 95% CI [1.18;1.63], p < 0.0001), whereas no significant difference was observed between young and old patients (OR 1.13, 95% CI [0.95;1.34], p = 0.149). Findings are illustrated in a Cox-regression analysis (Fig. 1).

Fig. 1: Long-term survival of M-TEER patients, stratified by age. Red: 50–69 years (young patients); green: 70–79 years (old patients), and blue: 80–99 years (very old patients).

Frailty

Patients were stratified by the pre-described care levels. Individuals with no impairments of independence and abilities formed the largest group (care level 0, n = 3665, 79.1%). Two-hundred sixty-five (5.72%) patients had minor impairments of independence and abilities (care level 1), and n = 679 (14.7%) were assessed to have significant impairments (care level 2). For reasons of clarity, patients with heavy, severe, and severe impairments of independence and abilities with special requirements for nursing care were group together (n = 287, 6.2%, care levels 3–5). Baseline characteristics divided by the level of impairments of independence can be found in Table 2**.** With increasing level of care the survival probability was significantly reduced as compared to patients with no impairments of independence and abilities (care level 1: OR 1.46, 95% CI [1.21;1.75], p = 0.0001; care level 2: OR 1.49, 95% CI [1.32;1.67], p < 0.0001; care level 3–5: OR 1.75, 95% CI [1.49;2.05], p < <0.0001). The impact of impairments of independence and abilities on long-term survival is illustrated in Fig. 2**.**

Fig. 2: Long-term survival of M-TEER patients, stratified by impairments of independence and abilities. Red: individuals with no impairments of independence and abilities formed the largest group (care level 0); green: individuals with minor impairments of independence and abilities (care level 1); blue: individuals with significant impairments (care level 2); purple: individuals with heavy, severe, and severe impairments of independence and abilities with special requirements for nursing (care level 3–5).

Comorbidities and demographic aspects

Chronic pulmonary obstructive disease (COPD), chronic renal insufficiency, dementia and diabetes mellitus type II as the most important non-cardiac co-morbidities were analysed illustrating that long-term survival of patients undergoing M-TEER was influenced. A small share of patients did not suffer from any of the before mentioned comorbidities (n = 821, 16.7%). Most of the individuals presented with one non-cardiac comorbidity (n = 1765, 36.0%), followed by the group with two non-cardiac comorbidities (n = 1680, 34.3%). For reasons of clarity, patients with three or more non-cardiac comorbidities were pooled together (n = 630, 12.9%). Cox-regression analysis revealed that with increasing number of non-cardiac comorbidities survival probability decreases significantly (one non-cardiac comorbidity: OR 1.36, 95% CI [1.17, 1.59], p < 0.001; two non-cardiac comorbidities: OR 1.73, 95% CI [1.48;2.01], p < 0.001, three or more non-cardiac comorbidities: OR 2.04, 95% CI [1.71;2.43], p < 0.001). The influence of non-cardiac comorbidities on the survival of patients undergoing M-TEER is plotted in Fig. 3.

Fig. 3: The influence on non-cardiac comorbidities on long-term survival of patients undergoing M-TEER. Non-cardiac comorbidities included chronic obstructive pulmonary disease, chronic kidney disease, dementia, Type two diabetes mellitus. Red: no non-cardiac comorbidity; green: one non-cardiac comorbidities; blue: two non-cardiac comorbidities; purple: three to four non-cardiac comorbidities.

Female sex (OR 0.73, 95% CI [0.67;0.80], p < 0.001) and obesity (OR 0.89, 95% CI [0.81;0.98], p = 0.027) have a protective effect, whereas right heart failure at baseline (OR 1.83, 95% CI [1.65;2.03], p < 0.001) significantly impairs long-term survival. Other demographics which were evaluated to influence survival are displayed in Table 3.

Variable | OR | 95% CI | p-value
Age group: 70–79 years | 1.13 | 0.95;1.34 | 0.149
Age group: 88–99 years | 1.39 | 1.18;1.63 | <0.0001
Care level 1 | 1.46 | 1.21;1.75 | <0.0001
Care level 2 | 1.49 | 1.32;1.67 | <0.0001
Care level 3–5 | 1.75 | 1.49;2.05 | <0.0001
One non-cardiac comorbidity | 1.36 | 1.17;1.59 | <0.0001
Two non-cardiac comorbidities | 1.73 | 1.48;2.01 | <0.0001
Three and more non-cardiac comorbidities | 2.04 | 1.71;2.43 | <0.0001
Female sex | 0.73 | 0.67;0.80 | <0.0001
Number of clips | 1.00 | 1.00;1.00 | 0.147
Right heart failure | 1.74 | 1.58;1.92 | <0.0001
Atrial fibrillation | 1.08 | 0.96;1.22 | 0.173
Obesity | 0.89 | 0.81;0.98 | 0.0274
Urban area | 0.96 | 0.85;1.04 | 0.434

Health economic aspects

Overall medical expenses 12-months before the procedure were equal to 12-months after M-TEER (12-months before: 5796€ [856.5;14,856.0] vs. 12-months after: 4.184€ [370;15,316]). The number of doctor patient contacts in the ambulatory setting remained unchanged (12-months before: 19 [14;25] vs. 12-months after 17 [11;24], OR 0.99, 95% CI [0.98;1.00]). The number of heart failure hospitalizations (HFH) 12-months before M-TEER were higher as compared to 12-months after the procedure (12-months before: Mean 0.8 vs. 12-months after: 0.68; OR 1.14, 95% CI [1.06;1.23]). Findings, stratified by age group and level of impairment are listed in Table 4**.** Access to care was equally distributed between urban and rural areas (OR 0.94, 95% CI [0.85;1.04], p = 0.245) in Germany.

 | Groups | 12-months before M-TEER | 12-months after M-TEER
Health care costs | 50–69 years | 7.206€ [1.102;19.408] | 6.318€ [609,8; 23.627,2]
 | 70–79 years | 5.859€ [917;15.187] | 4.697€ [470;16.772]
 | 80–99 years | 4.924,5€ [642.5;12.183] | 3.536€ [358;12.764]
 | No impairments | 4.084€ [429;10.332] | 3.463,5€ [356,5;13.163]
 | Care level 1 | 7.692€ [2.885;15.736] | 4.503€ [395;14.521]
 | Care level 2 | 9.027€ [3.120;19.061] | 5.578€ [611,5;18.789]
 | Care level 3–5 | 13.218€ [4.973;25.607] | 5.984€ [561;18.504]
Outpatient patient doctor contacts | 50–69 years | 17 [12;23] | 18 [13;25]
 | 70–79 years | 19 [13;25] | 20 [14;26]
 | 80–99 years | 19 [14;25] | 18 [14;24]
 | No impairments | 18 [13;24] | 19 [14;25]
 | Care level 1 | 20 [14;26] | 18 [14;25]
 | Care level 2 | 20 [15;26] | 19 [14;26]
 | Care level 3–5 | 20 [15;27] | 19 [14;25]